Search

Annually, the thermal coal industries produce billion tons of fly-ash (FA) as a waste by-product. Which has been proficiently used for the manufacture of FA based geopolymer concrete (FGC). To accelerate the usage of FA in building industry, an innovative machine learning techniques namely gene expression programming (GEP) and multi expression programming (MEP) are employed for forecasting the compressive strength of FGC. The comprehensive database is constructed comprising of 311 compressive strength results. The obtained equations relate the compressive strength of FGC with eight most effective parameters i.e., curing regime (T), time for curing (t) in hours, age of samples (A) in days, percentage of total aggregate by volume (% Ag), molarity of sodium hydroxide (NaOH) solution (M), silica (SiO2) solids percentage in sodium silicate (Na2SiO3) solution (%S), superplasticizer (%P) and extra water (%EW) as percent FA. The accurateness and predictive capacity of both GEP and MEP model is assessed via statistical checks, external validation criteria suggested by different researcher and then compared with linear regression (LR) and non-linear regression (NLR) models. In comparison with MEP equation, the GEP equation has lesser statistical error and higher correlation coefficient. Also, the GEP equation is short and it would be easy to use in the field. So, the GEP model is further utilized for sensitivity and parametric study. This research will increase the re-usage of hazardous FA in the development of green concrete that would leads to environmental safety and monetarist reliefs.

Recently, the capture of carbon dioxide (CO2) using alkaline waste and byproducts has garnered considerable interest. Construction sludge may be categorized as alkaline waste, as it often exhibits high alkalinity during its generation or intermediate treatment. Hence, researchers have attempted to accelerate pH neutralization and recycle alkaline construction sludge by curing it under a high CO2 concentration. By exposing concentrated CO2 gas to an alkaline sludge, cement hydrates such as calcium hydroxide and calcium–silicate–hydrate gels form calcium carbonate (CaCO3). Subsequently, the generation of CaCO3 is expected to reduce the pH of the sludge. However, the amount of CO2 captured in sludge has not been investigated extensively, unlike those of other alkaline wastes. Therefore, the amount of CO2 captured in alkaline sludge that is associated with pH neutralization is evaluated in this study. It is demonstrated that accelerated carbonation tests using a CO2 incubator and carbonate content evaluation tests based on the gas pressure method successfully reveal the amount of CO2 captured in the alkaline sludge that is associated with pH neutralization. Additionally, the test results show that the amount of mCO2 (i.e., the amount of CO2 captured per 1 g of dry mass of alkaline sludge) increases with ΔpH (ΔpH is the difference between the initial pH and the pH after the alkaline sludge is neutralized). A maximum of 0.021 g of CO2 is captured per 1 g of dry mass of alkaline sludge when the addition ratio of quicklime AQL = 3% and 0.040 g when AQL = 6%. The CO2 capture ratio mCO2/mCO2max, which represents the ratio of CO2 captured in the sludge to the maximum capturing capacity, increases with ΔpH. CO2 capture ratios of up to 90.0% and 84.9% are recorded when AQL = 3% and AQL = 6%, respectively. It is discovered that a higher AQL results in a higher mCO2. Moreover, the test results indicate that a higher AQL causes a more significant change in the CO2 capture ratio, even when the pH decreases slightly.

Limestone calcined clay cement (LC3) is a new type of low-carbon cement that can reduce energy consumption and carbon dioxide emissions while meeting the performance requirements of ordinary cement. In this study, polypropylene (PP) fibers were mixed into limestone calcined clay cement-based materials to make new low-carbon ECCs. In this study, a total of 24 sets of specimens were designed for 4 groups of curing ages and 6 types of mix ratios. The compressive load–displacement data were measured the compressive curve characteristics were analyzed then, a compressive constitutive model of the composites was deduced and obtained. Through XRD, SEM-EDS and MIP experiments, the reasons and laws of the compressive strength ranges of adding PP fibers and LC3 to engineered cementitious composites (LC3-PP-ECCs) are further explained from the perspective of the pore size, microstructures and hydration products. The results show that, after 28 days, the compressive strength values of LC3-PP-ECCs generally decreases with increasing PP fiber content and the combined effect of PP fibers and hydration products causes the compressive strength of LC3-ECCs with 0.5% PP fibers to drop sharply. In addition, the specimens showed better properties in terms of toughness, ductility and energy absorption. However, in the microstructures, the addition of PP fibers will cause more internal defects and flaws. This results of this study can provide some theoretical experience and technical support for the engineering application of LC3-ECCs.

This study explores the coupling effect of pond ash (PA) and polypropylene (PP) fiber to control the strength and durability of expansive soil. The PA is used to chemically treat the expansive soil and PP fiber is adopted as reinforcement against tensile cracking. The sustainable use of PA and PP fiber are demonstrated by performing mechanical (i.e. unconfined compressive strength, split tensile strength and ultrasonic pulse velocity), chemical (pH value, electrical conductivity and calcite content), and microstructural analyses before and after 2nd, 4th, 6th, 8th and 10th freezing-thawing (F-T) cycles. Three curing methods with 7 d, 14 d and 28 d curing periods are considered to reinforce the 5%, 10%, 15% and 20% PA-stabilized expansive soil with 0.25%, 0.5% and 1% PP fiber. In order to develop predictive models for mechanical and durability parameters, the experimental data are processed utilizing artificial neural network (ANN), in association with the leave-one-out cross-validation (LOOCV) as a resampling method and three different activation functions. The mechanical and durability properties of the PA-stabilized expansive soil subgrades are increased with PP fiber reinforcement. The results of ANN modeling predict the mechanical properties perfectly, and the correlation coefficient (R) approaches up to 0.96.

This paper presents an investigation on the adoption of isothermal microwaving in curing ultra-high performance concrete (UHPC) embedded with steel fiber reinforcement. The plain UHPC and the one with varying levels of steel fiber reinforcement are developed by microwave heating at 80 °C for 30 min. The compressive and flexural strength, hydration products, microstructure and interfacial structure of the mixes are evaluated. The results show that, besides the common reactions of hydration, pozzolanic reaction, carbonation, a reaction consuming calcium carbonate is found to occur in the system; furthermore, a Hayne-like phase and a cancrinite-like phase are formed. The formation of them is reduced by increased reinforcement. The accelerated effects of microwave on reaction are found to vary with reinforcement. Accelerating hydration is beneficial from increased fiber contents. Steel fiber reinforcement is more effective in increasing the compressive and flexural strength of UHPC cured with microwaves than cured under standard conditions.

In the case of cement-stabilized soils cured under the influence of overburden stress, it is necessary to consider two different timelines of cementation and consolidation, along which the structures of stabilized soils evolve. These two timelines are interrelated and ought not to be considered separately, especially in the early stage of curing when significant structural changes occur. In this study, the strength and deformation characteristics of cement-stabilized clay subjected to overburden stress during curing was investigated using an unconfined compression test apparatus. For this purpose, three types of specimens were prepared by stabilizing very soft clay with different amounts of cement. Overburden stress was applied for three different time durations during curing. In the series of unconfined compression tests conducted on the specimens with no overburden stress applied during curing, the axial stress initially increases rapidly, then was maintained before finally dropping. In the series of tests with overburden stress applied during curing, the axial stress continues to increase gradually before rapidly declining. The values of unconfined compressive strength are larger for the specimens subjected to overburden stress during curing. The values of the unconfined compressive strength also increase linearly as the duration of applied overburden stress increases. The increase in strength apparently occurs due to increasing dry density accompanied by a decrease in the water content due to the drainage of pore water during the application of overburden stress.

This research aimed to enhance the durability of concrete at a marine site by using ground palm oil fuel ash (GPOFA). Portland cement type I had been replaced by GPOFA at various replacement levels of 0–50% by weight of binder, with three different strength grades. Cubical concrete specimens with embedded steel bars at various covering depths were cast to determine chloride ingression and steel corrosion. After curing for 28 days, the concrete specimens were placed in a marine environment. The compressive strength, total and free chloride ingress, and embedded steel corrosion of the specimens were determined after subjecting them to tidal zone conditions for 7 years. The results show that the concrete specimens containing GPOFA at replacement levels of 15–35% by weight of binder provided the best durability performances at the marine site, with lower compressive strength loss and higher chloride and steel corrosion resistances than ordinary Portland cement concrete. This indicates that GPOFA in a replacement levels of 15–35% by weight of binder, with a maximum W/B ratio of 0.45, can be used efficiently in concrete to enhance the service life of marine concrete structures.

Alkali-activated concrete (AAC) has attracted considerable attention since its first use as an alternative material to the well-known traditional Portland cement concrete (PCC) due to their superior properties and environmental impact. In this paper, a comprehensive review on the present knowledge about the AAC in terms of historical background, environmental impact, constituent materials and characteristics of alkali-activated slag concrete (AASC) is presented. The following topics are reviewed in details for AASC: historical background, environmental impact, constituent materials, reactions mechanism, hydration products, compressive strength, stress–strain behavior, elasticity modulus, Poisson’s ratio, tensile strength, bond characteristics with reinforcing steel bars and behavior under elevated temperature. Most studies have demonstrated the superior mechanical properties of AASC and their applicability in the construction engineering field. Moreover, AASC exhibits bond performance and elevated temperature resistance better than PCC. However, the review reveals that more studies and investigations related to mix design including mix proportions, mixing procedures and curing regime, with which the AASC could demonstrate the best engineering properties, are required.

As cement manufacturing is associated with CO2 emissions that contribute to environmental problems, cement usage must be reduced and alternative aggregates must be developed. Thus, we developed and evaluated a mortar that uses feldspar as a fine aggregate, which does not require additional mineral admixtures. Feldspar and conventional plastering sand-based specimens were prepared with a fine aggregate proportion of 75%, 80%, or 85%. The compressive strength test results confirmed that the strength of the feldspar-based mortar was 1.1–4.5 times higher than conventional plastering sand-based mortar. Microstructure analysis after 3 and 7 d of curing revealed the existence of capillary micropores and gel pores, which improved water tightness. C-S-H and C-S-H gel hydration was also observed at the early stage, and the amount of C-S-H also increased. Further, an additional reaction may have occurred between feldspar compounds, SiO2 and Al2O3, and Ca(OH)2 that accelerated C-S-H production and contributed to the higher compressive strength. The relatively high-strength feldspar-based mortar is expected to reduce cement dependency, which can be achieved using a fine-aggregate feldspar mixing ratio according to project requirements. Thus, the proposed fine aggregate alternative can help alleviate the environmental problems associated with cement usage. It also has potential as an eco-friendly building material.

One of the sustainable alternatives to Portland cement is geopolymer concrete consisting of industrial waste. Practical application of geopolymer concrete is restricted as it requires the use of high temperature to develop compressive strength. This study aims to develop a mixture design for geopolymer prestressed concrete specifically designed to take prestressing force using ambient curing technique and compare its performance with the same grade of Portland cement concrete mix. As ambient curing technique is used for geopolymer concrete hence a combination of blast furnace slag and fly ash is taken as source materials and due to ease of availability and economy, sodium hydroxide and silicate are chosen as activators. After several trial mixtures, M 40 grade of geopolymer concrete is developed using an equal proportion of fly ash and ground granulated blast furnace slag (GGBFS) as source material. GGBFS provides early strength at ambient curing in geopolymer concrete and hence was incorporated with fly ash. 3 ply of 3 mm diameter bars were used as pre-tensioning wire. Load v/s deflection graph for non-prestressed geopolymer concrete beams and beams with same grade Portland cement concrete show that the load-carrying capacity of both beams was at par. It was also observed that prestressed geopolymer concrete beams which were cured under ambient curing developed sufficient strength and were equally capable of carrying the load as compared to Portland cement concrete beams. Load carrying capacity increased in prestressed Portland cement concrete beams increased by 78% while in prestressed geopolymer concrete beams the increase was 83% and also the deflection of both prestressed beams was more compared to non-prestressed beams. This indicates that sustainable material can be effectively utilized in prestressing work without comprising on strength.

The present study investigates the development of artificial stones containing travertine powder, fine sand, and travertine sludge. The stone powder and sludge were considered as waste. The main target of this study is to reuse and recycle the travertine waste to produce sustainable artificial stone. Considering the used solid components, three groups of artificial stones, including: (1) the combination of powder and sludge, (2) the combination of powder and sand, and (3) the combination of powder, sludge, and sand, were proposed. The percentage of each solid component per total solid components, two kinds of epoxy resins, the percentage of the used resin per total solid components, and curing temperature were selected as the variables for preparing the artificial stones. Based on the number of variables and their levels, the Taguchi approach was employed to design mix proportions in the three groups. After conducting the compressive and flexural tests of the proposed mix proportion, the compressive and flexural strengths of un-conducted mix proportions were predicted using the Taguchi method. The results show that the effect of each variable on the compressive and flexural strengths of the stones of various groups are different. The samples prepared with epoxy resin type 828 are stronger than those prepared with epoxy 557. The best sample has the compressive and flexural strengths of 67.3 and 60.7 MPa, respectively. This mix proportion included 90% travertine powder, 10% travertine sludge, and 30% epoxy resin 828 per total solid components and was cured at 60 °C for 4 h.

This paper presents the effect of nano-CaCO3 (NC) on the compressive strengths and durability properties of high volume slag (HVS) and high volume slag-fly ash (HVS-FA) blended concretes. The study examined the improvement in early and later age compressive strengths and durability properties such as sorptivity, volume of permeable voids, rapid chloride penetration and drying shrinkage of HVS concrete containing 69% blast furnace slag (BFS) and HVS-FA concrete containing combined BFS and fly ash (FA) content of 69% due to the addition of 1% NC. Results show that the addition of 1% NC improved the compressive strengths of HVS and HVS-FA concretes significantly by 43% and 28%, respectively at 3 days compared to the control HVS and HVS-FA concretes without NC and exceeded the compressive strengths of control OPC concrete at later ages. It is also found that 1% NC inclusion reduced the water sorptivity of HVS and HVS-FA concretes reasonably after 28 days of curing and reduction is greater after 90 days of curing exhibited comparable water sorptivity to OPC concrete. Significant improvement is also observed in reducing the volume of permeable voids and controlling the drying shrinkage strain at early age as well as later ages of both HVS and HVS-FA concretes due to 1% NC inclusion. Outstanding resistance against chloride ion penetration is also observed in HVS and HVS-FA concretes due to addition of 1% NC to the very low level of chloride ion penetration according to ASTM standard. SEM and EDS analysis revealed a denser microstructure of paste and interfacial transition zone (ITZ) around aggregates.

The high strength and durability of high-performance concrete (HPC) may be significantly reduced by shrinkage cracking. The use of reactive magnesium oxide (MgO) can reduce shrinkage of cement-based materials due to its expansive properties. This study intends to analyse the validity of MgO as shrinkage-reducing agent in recycled aggregate HPC. To do so, ten HPC mixes with 0%, 25%, and 100% of both early-age (7-days air curing) and matured (6-month air curing) RA were produced. In half of the mixes, 10% ordinary Portland cement was replaced with MgO. The use of MgO slightly worsened the mechanical behaviour of HPC, especially when combined with large amounts of RA. On the other hand, the expansion of MgO fully offset the autogenous shrinkage of HPC and reduced total shrinkage by around 20–40%. Water storage of RA, and its deferred release over time, produced a more efficient hydration of MgO, which in turn led to a further reduction of autogenous shrinkage. However, the increase of drying shrinkage caused by RA was greater than this decrease of autogenous shrinkage due to MgO, so the higher the RA content of HPC the lower the total shrinkage reduction when adding MgO. Thus, the decrease of total shrinkage caused by MgO was compensated by the shrinkage increase because of RA when adding amounts above 35% early-age RA and 42% matured RA. Therefore, despite the suitability of MgO as shrinkage-reducing agent in recycled aggregate HPC, its effectiveness was reduced with increasing amounts of RA., Spanish Ministry of Universities, MICINN, AEI and ERDF [grant numbers FPU17/03374; EST19/00263; PID2020-113837RB-I00; 10.13039/501100011033]. The authors also acknowledge the support of the Foundation for Science and Technology, CERIS Research Centre and Instituto Superior Técnico, the Junta de Castilla y León [grant number UIC231], and the University of Burgos [grant number Y135.GI].

The present study introduces the preparation of thermal insulation geopolymer bricks using ferrosilicon slag and alumina waste. Compressive strength, bulk density, cold and boiling water absorption, apparent porosity, thermal conductivity, and Fourier-transform infrared spectroscopy were used to characterized the geopolymer paste. Ferrosilicon slag suffers from low alumina content. Thus, alumina is added to compensate for this deficiency. Pristine ferrosilicon slag and the SiO2/Al2O3 (Si/Al, ratio = 2) sample were prepared at different NaOH concentrations (i.e., 6, 8, 10, and 12 M; Na2SiO3/NaOH ratio = 2.5), different curing times (i.e., 3, 7, 14, and 28 days), and room temperature. The 8 M NaOH concentration achieved the best compressive strength. Accordingly, different Si/Al ratios were prepared and tested at 8 M NaOH, room temperature, and different curing times (i.e., 3, 7, 14, and 28 days). Results indicate that increasing the alumina content enhances the geopolymer properties but reduces the compressive strength of the prepared geopolymer. The sample with Si/Al ratio = 1 exhibited a higher compressive strength (10.9 MPa) than the other Si/Al ratios (i.e., 4, 3, 2, and 0.5) and the pristine ferrosilicon slag after 28 days of curing and at 8 M NaOH. The obtained value is consistent with the ASTM C62 and Egyptian standards. Furthermore, the addition of alumina waste decreased the thermal conductivity of the prepared geopolymer bricks. The present study introduces the preparation of thermal insulation geopolymer bricks using ferrosilicon slag and alumina waste. Compressive strength, bulk density, cold and boiling water absorption, apparent porosity, thermal conductivity, and Fourier-transform infrared spectroscopy were used to characterized the geopolymer paste. Ferrosilicon slag suffers from low alumina content. Thus, alumina is added to compensate for this deficiency. Pristine ferrosilicon slag and the SiO2/Al2O3 (Si/Al, ratio = 2) sample were prepared at different NaOH concentrations (i.e., 6, 8, 10, and 12 M; Na2SiO3/NaOH ratio = 2.5), different curing times (i.e., 3, 7, 14, and 28 days), and room temperature. The 8 M NaOH concentration achieved the best compressive strength. Accordingly, different Si/Al ratios were prepared and tested at 8 M NaOH, room temperature, and different curing times (i.e., 3, 7, 14, and 28 days). Results indicate that increasing the alumina content enhances the geopolymer properties but reduces the compressive strength of the prepared geopolymer. The sample with Si/Al ratio = 1 exhibited a higher compressive strength (10.9 MPa) than the other Si/Al ratios (i.e., 4, 3, 2, and 0.5) and the pristine ferrosilicon slag after 28 days of curing and at 8 M NaOH. The obtained value is consistent with the ASTM C62 and Egyptian standards. Furthermore, the addition of alumina waste decreased the thermal conductivity of the prepared geopolymer bricks.

Colloidal nanosilica is an innovative grouting material, currently used in tunnelling applications for grouting fine cohesionless soils when environmental limits prevent the application of other solutions. Despite a large number of applications, knowledge of operational parameters for grouting such as gelling time and dynamic viscosity is very limited. Furthermore, the influence of the type of nanosilica (in terms of SiO2 concentration) and accelerators on the achievable mechanical performance of injected soils has never been investigated. In this work, a laboratory test campaign based on two commercial colloidal nanosilica and two accelerators was conducted. Once the operational parameters had been investigated, four different soils have been grouted and, after curing, mechanically tested. The results, in terms of gelling time and viscosity order of magnitude, are crucial for the correct functioning of a grouting. Furthermore, the results of the uniaxial compression tests, the indirect tensile tests and the direct shear tests have shed light on the potential of colloidal nanosilica and on the differences between the chemicals.

This study determines the suitability of using shredded waste plastic and waste ceramic powder (WCP) to produce interlocking concrete blocks (ICB). The study adopted a concrete mix ratio of 1:2 containing 20 % partial replacement of sand with ceramic waste. The compressive strength, splitting tensile strength, and water absorption of the interlocking concrete blocks were determined, after 7, 28, and 90 days of curing. The ICBs developed include mixes containing plastic fibres in proportions 0, 0.5, 1, 1.5, and 2% by weight of concrete, and a control mix with zero ceramic waste and plastic fibres. The microstructure and mineralogy of selected samples were observed using a scanning electron microscopy (SEM) and XRD (X-ray diffraction), respectively. From the result, compressive strength and splitting tensile strength of the interlocking concrete blocks increased with an increasing plastic fibre content. Also, the microscale tests revealed good compactness, and interparticle reactions in the matrix. Thus, the study recommends 2% of plastic fibre content for the production of interlocking concrete blocks.

In recent years, serious environmental problems induced by plastic wastes have drawn considerable attention across the world and new initiatives have been adopted to recycle plastic wastes into construction materials. One of the promising initiatives is the use of plastic waste as the only binding phase to make concrete/mortar-like construction materials. However, how key engineering properties of concrete/mortar-like materials with melted plastic as the only binder change with material composition and curing conditions are not well known. This paper aims to investigate the effect of curing conditions and granular material size on the mechanical properties (compressive and splitting tensile strengths) of a mortar with melted plastic waste (high density polyethylene (HDPE) and low density polyethylene (LDPE)) as the only binder (MPB: mortar with melted plastic waste binder). Moreover, it presents a study conducted in the city of Bamako (Mali) to evaluate the use of MPB to make interlocking paving blocks for use on non-traffic areas in residential or municipal construction projects. Two curing conditions, namely, air dry at ambient temperature and water curing were used for this research. Moreover, the size of the granular materials (sand and gravel) was varied in order to assess its impact on the properties of the corresponding MPB sample formulations with given plastic content and HDPE/LDPE (H/L) ratio. Granular material size and curing conditions were found to have significant impact on the mechanical strengths of the MPB materials. Regardless of age and H/L ratio, the MPB samples cured in water showed lower strength (compressive and tensile) than the specimens cured at ambient temperature under controlled laboratory conditions, while adding coarse granular materials helped to improve these strength properties. Furthermore, the mechanical performance of the proposed MPB-interlocking paver is superior to that of the interlocking Portland cement-based pavers that are commercially available on the Bamako’s market. Moreover, the cost of the Portland cement-less MPB-paver will be substantially lower than that of the Bamako’s commercial Portland cement-paver. The obtained results place this MPB material as a promising candidate for making interlocking pavers or other products, while reducing the amount of plastic waste to be managed and the cost of interlocking pavers.

Concretes separately made with the mixtures of five percent weight of wheat husk ash, corn straw, and sorghum straw. The concrete obtained from each mixes was subjected to both normal curing and modified curing. The modified curing contained sulfuric and nitric acids proportional to the nitrous and sulfurous oxides in industrial environments. The time for the two curing types was 7, 28, and 90 days of age. Cylindrical specimens with embedded steel rods of the concrete were made to measure the corrosion resistance, which showed that the modified curing conditions affected the properties analyzed in the studied concretes. These results also show that the concretes made with wheat and sorghum ash improve compressive strength, density, and corrosion rate under normal and modified curing conditions. Therefore, some of the studied mixtures represent an option to be considered for supplementary cementitious materials (MCSs). The samples with corn ash, on the other hand, showed properties that make them unsuitable for supplemental cementitious materials.

Biochar has unique properties such as its porous structure, specific surface area, and stable chemical properties. The rice husk is characterized by its high content of silica, and that during the pyrolysis process it generates a considerable amount of biochar that can be used in different processes. The aim of this work is to evaluate several biochars from the pyrolysis process in the reactivity of lime pastes. For this, biochar has been obtained at four different temperatures (450, 500, 550 and 600 °C), and they have been characterized by XRF, XRD, ICP-EOS, and particle size distribution, to determine their phases and their chemical composition. Biochar has been replaced in lime pastes in different proportions (5, 10, 15, 20, 25 and 30%), and exposed to different curing times (1, 3, 7, 14, 28, 56, 90 and 180 days). It has been found that all the replacements show reactivity within the lime pastes and that the percentage of 25% in all the biochar tested could be an adequate replacement., Rice husk; Pyrolysis; Biochar; Reactivity; Lime pastes.

Dry-cured pork loin is a very popular meat product in Mediterranean countries. Pork-loin is manufactured rubbing curing salts, nitrite and nitrate, and spices on the surface of the loin which is then dry-cured or smoked for several months. Although nitrite-derived compounds are crucial for the microbiological safety and development of a distinct flavour, there have been recent concerns about the adverse health effects of nitrite-derived compounds driving to the reduction of curing agents in meat products. In this study, we have evaluated the differences in microbiota and aroma of dry-cured pork loins manufactured with or without paprika and reduced ingoing amounts of nitrate and nitrite. Staphylococcus dominated the microbiota of pork loins without paprika, regardless of the nitrite and nitrate reduction. On the contrary, the reduction of nitrite and nitrate in loins with paprika had an important effect on the microbiota. In these loins a codominance of Staphylococcus and Bacillus together by Enterobacteriaceae occurred. Moreover, paprika addition and reduction of nitrite and nitrate seemed to promote proliferation of lactic acid bacteria. Occurrence of these genera was correlated with the generation of free amino acids and their derived volatile compounds setting clear differences in the aroma profile of dry-cured loins., This work was supported by grant RTI2018-098074-B-I00 from MCIU/AEI/FEDER.

Highlights • Ultrasound-assisted tumbling (UAT) treatment significantly increased the NaCl content in pork. • The applied NaCl transfer model could accurately describe the NaCl diffusion coefficient. • Moderate UAT treatment improved the tumbling yield, water-holding capacity, and textural properties of pork. • Moderate UAT treatment facilitated the protein extraction. • Excessive UAT treatment led to protein denaturation., The present study aimed to investigate the impact of ultrasound-assisted tumbling (UAT; 20 kHz, 100, 300, 500 and 700 W) with different treatment time (30, 60, 90 and 120 min) on the diffusion and distribution of NaCl as well as the change of pork texture properties during curing. Results showed that in comparison with the single tumbling (ST), the NaCl content and the NaCl diffusion coefficient were increased along with UAT treatment (P

When Portland cement (PC) is used for soil stabilisation, exposure to sodium chloride (NaCl) is a major problem in geotechnical engineering. NaCl's effect decreases the soil's structural stability and weakens its mechanical performances. The recycled powder recycled tyre (PRT) can be utilised to improve the mechanical characteristics of soil while reducing the landfills matters. The resistivity to chloride of cement clay after 7 days, 14 days and 28 days of curing were evaluated. Compressive strength tests (UCS) were performed. Half of which were performed on the control sample (unexposed) and half on the sample exposed to NaCl. The addition of 3 % PRT increased the UCS (qu) value under standard conditions and when exposed to NaCl. The same trend was observed for the addition of 5 % and 10 % PRT. The exposure reduced the UCS value, and the higher PRT dosage showed a better outcome. The analysis has shown that, when exposed to NaCl, cement hydration products, such as calcium silicate hydrate (CSH) and calcium aluminate hydrate (CAH), are degraded, causing huge voids.

Using the wastes as a recycled concrete aggregate (RCA) is a promising technology to reduce the impact of construction and demolition wastes on the environment and the shortage of natural resources. However, higher permeability of RCA leads to greater absorption, affecting the RCA concrete's long-term performance. In general, the soil in Iraq contains a high sulfate level, accelerating concrete deterioration reducing concrete strength, and increasing concrete spalling and cracking. The aim of this study is to investigate the impact of sulfate environment on the mechanical properties of pretreated RCA concrete using a PVA agent. The normal aggregate was replaced in four portions of 8 %, 16 %, 24 %, and 32 % RCA, with the same grading and max size as normal aggregate. Two w/c ratios of 0.50 and 0.3 were used with two curing systems, namely sealed and unsealed conditions. The RCAs were socked in 0.5 % PVA of the water volume. The durability of RCA concrete was also experienced by sulfate attack immersing the concrete cubes in magnesium sulfate heptahydrate (MgSo4.nH2O) solution for 150 days after 28 days from casting with the wetting and drying cycle. The compressive strength results showed that the mixes with RCA pre-soaked in PVA have higher strength than the reference mix. For durability, the concrete mix with 32 % RCA exhibited the best durability. When the increased amount of RCA pre-soaked in PVA, the hydration increased, and internal voids decreased. Using 24 % RCA replacement with the sealed curing condition gives a 1.2 % increase in absorption, which is less than the unsealed curing condition of a 1.8 % increase in absorption.

Hollow sandcrete blocks constitute more than 90% of residential building construction in developing countries especially in West Africa. Over-reliance on dredged river sands and conventional ordinary Portland cement (OPC) contributes to environmental degradation and post-construction problems such as swelling and shrinkage-induced cracks prevalent in construction projects. The study investigates potential utilization of locally available materials such as laterite, calcite and calcined clay as ternary and quaternary blends to replace cement and quarry dust as 100% replacement of river sand with the aid of Taguchi-Response surface methodology approach. Optimum ternary blend of 24% calcined clay +1% calcite +75% OPC is recommended to achieve volume stability, higher compressive strength and higher flexural load capacity. Alternatively, ternary blends of 24% calcite +4% calcined clay +72% OPC can also be utilized. The improved mechanical properties were attributed to the Na- and Ca-rich aluminosilicates provided by the blended cements. Successful utilization of ternary and quaternary blended cements to produce stronger, durable and eco-friendly sandcrete blocks depends on utilization of high binder-to-aggregate ratio, optimal combination of the constituents, appropriate water-cement ratio and curing/production method. Partial and 100% replacement of river sand with granite dust is possible and contributes to reduction of environmental problems caused by river dredging as well as cleaner, ecofriendly construction. Ternary and quaternary blended cements is recommended to avert post-construction problems such as swelling and shrinkage-induced cracks prevalent in construction projects., Sandcrete block; Calcite; Calcined clay; Ternary blended cement; Quarry dust; Quaternary blended cement

Ladle furnace slag (LFS) has been proposed as partial cement replacement due to its similar chemical composition with Portland cement. However, its mineralogical composition needs to be considered due to problems with expansive reactions and lower cementing activity. The objective of this study is to investigate the effect of particle size and mineralogical composition of LFS in cement-slag systems. The obtained results show a correlation between microstructural changes and macroscopic properties, lower mechanical performance and volumetric instability problems, although within the established limits in normal curing conditions. Therefore, it is concluded that LFS presents an interesting potential as cement replacement., This work was funded by the National Agency for Research and Development (ANID) DOCTORADO EN EL EXTRANJERO, BECAS CHILE/2019 – 72200568.

Fermented meat products are important not only for their sensory characteristics, nutrient content and cultural heritage, but also for their stability and convenience. The aroma of fermented meat products is unique and its formation mechanisms are not completely understood; however, the presence of nitrite and nitrate is essential for the development of cured aroma. The use of nitrite and nitrate as curing agents in meat products is based on its preservation activity. Even though their presence has been associated with several risks due to the formation of nitrosamines, their use is guarantee due to their antimicrobial action against Clostridium botulinum. Recent trends and recommendations by international associations are directed to use nitrite but at the minimum concentration necessary to provide the antimicrobial activity against Clostridium botulinum. This chapter discuss the actual limits of nitrite and nitrite content and their role as curing agents in meat products with special impact on dry fermented products. Regulatory considerations, antimicrobial mechanisms and actual trends regarding nitrite reduction and its effect on sensory and aroma properties are also considered.

The use of three different waste-based materials, i.e. ceramic recycled aggregate (CRA), mixed recycled aggregate (MRA), and coal bottom ash (CBA), as internal curing water reservoirs was investigated. Their effects as fine aggregates in the mortar phase of a hypothetical concrete with a low water-to-binder ratio were studied. The used binders were ordinary Portland cement and high-volume fly-ash-blended cement. The addition of MRA and CBA significantly decreased the autogenous shrinkage, whereas their negative effects on drying shrinkage and the compressive strength were minimal. However, the CRA had the worst effect on autogenous shrinkage but increased the strength of the specimens. This work has been carried out within the framework of the HACCURACEM project (BIA2017-85657-R), funded by the Ministry of Economy, Industry and Competitiveness, State Program for Research, Development and Innovation aimed at the challenges of Society, within the framework of the State Plan for Scientific and Technical Research and Innovation 2013–2016, Call 2017. We also thank the Xunta de Galicia (Spain) for the financial support through its pre-doctoral contracts program. Finally, we highlight the collaboration of the companies Votorantim Cimentos and Grupo BASF, for the contribution of some of the materials used in this research. Peer Reviewed Objectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables Objectius de Desenvolupament Sostenible::13 - Acció per al Clima Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura

3D-printing of geopolymers produced from lunar regolith is an interesting option for space in situ habitats. In this study, the influence of the severe lunar environmental conditions such as extreme temperature variations and vacuum on the physical and mechanical properties of lunar regolith geopolymers were investigated. Additionally, the effect of different amounts of urea as a geopolymer superplasticizer was evaluated. Utilization of urea was found to reduce the water needed to reach the same workability by up to 32%. Extrudability tests showed that mixtures containing 3 wt.% urea could be continuously extruded, and built up into a five layer structure without any noticeable deformation. Addition of urea decreased the compressive strength after exposure to the temperature variations of one lunar day–and–night cycle during curing. However, urea can prevent concrete degradation after the lunar cycle by increasing the amounts of air voids. X-ray tomography showed that the porosity became higher when urea was added to the samples, and increased markedly when the samples were cured in vacuum.

Geopolymer concrete is a more environmentally friendly alternative than conventional concrete because its production does not need cement. Instead, waste materials such as fly ash, rice husk ash, slag, etc. are used. This research studies the effect of the activator concentration (6–10 M), curing temperature (40–80 °C) and incorporation ratio of thermally and mechanically treated recycled aggregate (0–100%) on changes in the macrostructural properties of geopolymer concrete. All raw materials were previously characterized by thermogravimetric and differential thermal analysis, X-ray fluorescence and X-ray diffraction. Furthermore, a microstructural characterization was carried out on two geopolymer concrete mixes used as reference: one made with a natural aggregate and the other with a treated recycled aggregate. The interfacial transition zone between the treated recycled aggregate/natural aggregate and geopolymer paste was studied using SEM-EDS. A beneficial effect of the treated recycled aggregates on the compressive strength of geopolymer concrete was observed due to formation of silicate hydrated gel (CSH) and calcium aluminate silicate hydrated gel (CASH). However, a slight increase in the water absorption of geopolymer concrete and the mass of peels after 28 freezing and thawing cycles occurred because of the presence of residual porous cement mortar on the treated recycled aggregate surface.

K-struvite, the main hydrate of magnesium potassium phosphate (MKP) cements, dehydrates at ~50 °C, thus elevated temperatures at service conditions could affect cement properties and durability. In this study, properties and hydration of MKP cement without and with wollastonite were investigated at 20 and 50 °C. In hydrated pure MKP cement K-struvite decomposes progressively over time to MgKPO4·H2O at 50 °C, which leads to a strong reduction of solid volume and severe strength loss. The presence of wollastonite significantly slows down the decomposition rate of K-struvite, which is still observed after 393 days at 50 °C. K-struvite together with amorphous hydroxyapatite, M-(C)-S-H and CaK3H(PO4)2 from the wollastonite reaction result in a cement with good short and long-term strength at both 20 and 50 °C.

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG [Abstract] Compaction is one of the most important factors to be considered while manufacturing laboratory samples of cold in-place recycled (CIR) mixtures. In this study, the effect of three laboratory compaction procedures (static, gyratory, and impact) on the volumetric performance of CIR mixtures was investigated. CIR specimens were manufactured with the same proportion of added water and bitumen emulsion, and using several levels of compaction, varying the number of gyrations and blows. The volumetric properties were evaluated by different procedures, both before and after curing. A comparison between the laboratory results of the different tests, the design target values, and actual in-field values was performed. It was observed that gyratory compaction proved to be the most versatile and one that best represented the real compaction. The bulk density procedure by dimensions was useful for laboratory design; however, it overestimated the sizes of the air void content by more than 10% compared to the field values. Ministerio de Ciencia e Innovación; BIA2016-80317-R Ministerio de Ciencia e Innovación; BES-2017-079633 The authors would like to acknowledge the funding for the project BIA2016-80317-R from the Spanish Ministry of Science and Innovation, with an associated pre-doctoral scholarship for the training of research workers (FPI) BES-2017-079633. The authors would also like to express their sincere gratitude to ARIAS INFRAESTRUCTURAS, and CEPSA and ECOASFALT for their generous donation of RAP and bitumen emulsions, respectively for the present research. Finally, an acknowledgement to the Universidade da Coruña/CISUG for funding Elsevier's open access charge.

Drying shrinkage of alkali-activated binders are recognized as one of the most important properties towards quality assurance of the binders. In this study, results of experimental studies and predictive models developed to determine the drying shrinkage of alkali - activated blast furnace-fly ash mortars are presented and discussed. Different parameters were altered in the experimental study such as the content of GGBFS, FA, activator modulus (Ms), and curing temperature. Their effects on the drying shrinkage of the mortars were then evaluated. Artificial neural network (ANN) and Multiple Linear Regression (MLR) models were built to predict the drying shrinkage at 28 days using the above-mentioned parameters as inputs. The experimental results and ANN model predictions showed strong correlations. The prediction of 28-days drying shrinkage for the alkali-activated GGBFS-FA was more accurate using ANN than MLR.

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG [Abstract] This review collates findings from more than 100 scientific publications regarding the performance of several waste-based porous materials (WASPORs) as water reservoirs for the internal curing of concrete. Results obtained by using recycled concrete aggregates, crushed ceramics, coal bottom ash, artificial waste-based aggregates, different powder materials and porous fibres were included. The influence of these WASPORs on the consistence, hydration, setting, microstructure, density, strength, modulus of elasticity, autogenous deformation, drying shrinkage and durability properties of concrete were analysed. General recommendations for suitable characterization of WASPOR and mix design are also given. The differences in water absorption capacity between the different porous materials studied have been used for explaining several of the observed phenomena. A moderate water absorption capacity together with a quick water desorption capacity were found to be among the key factors that define the internal curing efficiency of the proposed WASPORs. This work has been carried out within the framework of the HACCURACEM project (BIA2017-85657-R), funded by the Ministry of Economy, Industry and Competitiveness, State Program for Research, Development and Innovation aimed at the challenges of Society, within the framework of the State Plan for Scientific and Technical Research and Innovation 2013-2016, Call 2017. We also thank Universidade da Coruña for the grants (Axudas Investigación UDC 2017) that facilitated the stay at the University of Bath (UK)

Pre­dicted sea level rise due to global warm­ing will ne­ces­si­tate the con­struc­tion of coastal de­fenses to pro­tect the pop­u­la­tions in the vicin­ity of the coasts. Large quan­ti­ties of con­crete will be re­quired with con­sec­u­tive in­creases in green­house emis­sions, hence an in­creas­ing need for al­ter­na­tive to Or­di­nary Port­land Ce­ment (OPC) ce­ments. Fea­si­ble po­ten­tial al­ter­na­tives could be found in al­kali-ac­ti­vated ce­ments , which also in­clude in­dus­trial by-prod­ucts or waste ma­te­ri­als. This pa­per pre­sents a lab­o­ra­tory study of con­crete mixes based on the al­kali-ac­ti­va­tion of an in­dus­trial by-prod­uct, ground gran­u­lated blast fur­nace slag (GG­BFS) and in­cludes an in­dus­trial waste, pa­per slugde ash (PSA) in the al­kali-ac­ti­va­tor mixes. The use of sea­wa­ter as mix­ing and cur­ing wa­ter was also ex­am­ined. The com­pres­sive strength and a num­ber of dura­bil­ity-re­lated prop­er­ties of al­kali-ac­ti­vated mixes in ma­rine en­vi­ron­ment were in­ves­ti­gated and com­pared to OPC sys­tems. The in­cor­po­ra­tion of pa­per sludge ash led to high early strengths, a de­crease in the ef­fec­tive poros­ity of al­kali-ac­ti­vated slag con­cretes and gen­er­ally a re­duced wa­ter ab­sorp­tion, and en­hanced the per­for­mance against chlo­ride ion at­tack in mixes with fresh­wa­ter, as well as the re­sis­tance of the ce­ments in sul­phate at­tack es­pe­cially when mixed with sea­wa­ter. The ad­di­tion of sea­wa­ter in the mixes in­creased the re­sis­tance to sul­phate at­tack and the com­pres­sive strength in al­kali-ac­ti­vated sys­tems, as op­posed to OPC con­cretes in which mix­ing and cur­ing in sea­wa­ter had dele­te­ri­ous ef­fects. The study gives promise for the suit­abil­ity of the tested al­kali-ac­ti­vated con­crete mixes in sea­wa­ter en­vi­ron­ments.

Natural table olives, a recognized unique foodstuff, are produced from raw drupe fruits of the cultivated olive Olea europaea L. without the use of alkali, for example, sodium, potassium hydroxide, or wood ash. Raw olives are bitter because of oleuropein, which must be partially or completely eliminated through leaching, acid hydrolysis, enzymatic or microbial hydrolysis, or oxidation. Naturally processed olives are commonly produced by either the archaic water curing method or fermentation, anaerobic or aerobic. Alternatively, olives can be allowed to dehydrate while on the tree, by heat or with solid salt. There are several challenges in the processing and commercialization of natural table olives to get a homogeneous color of the final product; achieve pitted and sliced olives with good texture; accelerate the debittering process, valorize the product, considering its nutritional characteristics and reducing salt levels; optimize the harvesting stage as well as to minimize spoilage drawbacks and many others.

The chapter presents a totally new approach to the preparation of bioadhesives for biocomposites starting from natural renewable materials and also waste natural materials. The specific oxidation of carbon-carbon bonds presenting vicinal hydroxyl groups by sodium periodate with the formation of two aldehyde groups is used for the following reasons: (1) For using waste cellulose to prepare composites. (2) For the preparation of plywood adhesives from soy flour where cleavage of its carbohydrates form a variety of both low and higher molecular weight nonvolatile, nontoxic aldehydes that react and cross-link the proteic part of the flour. Some aldehyde groups are also generated on the protein structure. (3) For the preparation of tannin + glucose (or sucrose) wood panels adhesives with the generation of lower molecular weight aldehydes reacting and curing the natural polyphenolic part of the tannins. (4) For the preparation of lignin adhesives by lignin cleavage with the generation of aldehydes reacting with lignin units and generating chemical species undertaking considerable rearrangements.

[EN] The corrosion resistance of ultra-high performance concrete (UH) made with different fibre contents and under distinct curing conditions was studied. No signs of carbonation were observed after 1 year of accelerated carbonation testing (3% CO2). The fibreless UHs¿ electrical resistivity was above 5000 ¿·m, although these values were 2-fold higher than a UH with 1% fibres and approximately 5-fold higher than a UH with 2% fibres. Concrete resistance to chloride penetration was also extremely high (the diffusion coefficient equalled 1.3·10¿13 m2/s) and curing temperatures of 60 °C or 90 °C improved even more these properties, while lack of curing made them slightly worse. Given these excellent properties, the corrosion rate in specimens submerged in chloride solution for 1 year was negligible (iCORR from 0.007 to 0.025 µA/cm2). These values remained stable with time, unlike the 50 MPa concrete at 2 months when iCORR starting to increase and was 12-fold higher after 1 year. The time estimated for corrosion onset in UH is on average about 150-fold higher than that of 50 MPa., Authors thank to the Spanish Government the financial support of project BIA2016-78460-C3-3-R and to the European Union¿s Horizon 2020 the financial support of ReSHEALience project (Grant Agreement No. 760824). Furthermore, authors would like to express their gratitude for the support of the Universitat Politecnica de Valencia. Funding for open access charge: CRUE-Universitat Politecnica de Valencia. The predoctoral scholarship granted to Josep Ramon Lliso Ferrando within the program "Formacion de Personal Investigador" from the Universitat Politecnica de Valencia (FPI-UPV-2018) is also gratefully acknowledged.

This chapter is an overview of the knowledge of ultrahigh performance concrete (UHPC) manufactured using inert residues as replacement of the different size of its composition. The feasibility of using different types of waste as supplemental cementitious materials is also described. First, the materials and composition of the UHPC are analyzed. The different types of waste used in the different studies consulted are described later. The manufacturing process and curing of the UHPC are also reviewed. Likewise, an analysis of the values corresponding to the most relevant mechanical properties of the UHPC obtained in the different studies is conducted. Finally, the durability of this type of concrete is analyzed. Permeability, porosity, carbonation, chloride ion penetration, the free thaw cycles resistance, and the fire resistance have been assessed.

The use of adhesive bonding is often an energy-intensive process, especially during the manufacturing and curing processes, which leads to the generation of CO2. In addition, further emissions of greenhouse gases might occur when disposing and burning adhesives at the end of life of a bonded structure. Within the current context, these are undesirable factors that limit the sustainability of this joining technology. Nonetheless, diverse possibilities exist for improving adhesive bonding procedures and drastically reduce their contribution to a global climatic change. For example, the use of lower-curing temperatures, complete recycling of adhesives, and the application of carbon-neutral materials are all methods that have recently gained importance. Another environmental issue associated with adhesive bonding is the difficulties faced in disassembling and separating bonded materials. In repair or recycling applications, it is often necessary to separate the adherend materials, often of dissimilar nature (for example, composite and aluminium). This is usually done via the application of large mechanical forces and extremely high temperatures, both of which can damage the adherends and preclude their recovery. Thus, demand exists for easily dismantlable adhesive joints that can be separated with an external stimulation. Extensive research has led to a set of different methods that can be used to create dismantlable adhesives. The most commonly used trigger for adhesive separation is the application of heat. Recently, various methods, such as infrared heating, induction heating, microwave heating, etc. have been used to apply this heat. In addition, new adhesives have become available that can be dismantled without heating, i.e. an adhesive with anisotropic strength, and a current-triggered adhesive, etc. have been proposed. This chapter describes the environmental aspects associated with the use of adhesion technology and details the use of dismountable adhesive layers to achieve greatly improved recyclability of bonded structures.

[EN] Four models were used to simulate nitrite uptake and water loss during pork meat curing with sodium nitrite: three empirical ones (the Azuara, the Peleg and the Zugarramurdi and Lupin) and one theoretical (the diffusional). By means of the Azuara and the Peleg models, the equilibrium moisture content and the equilibrium nitrite content were properly identified. Zugarramurdi and Lupin's model did not provide information about process parameters. The effective diffusivities of water (Dwe) and nitrite (DNe) were calculated. The activation energy (ENa and Ewa) was evaluated from the parameters of both the Peleg and the diffusional models. The results were similar; the Peleg model having the advantage of simplicity of calculation. The effect of meat anisotropy was confirmed from the diffusional model; the perpendicular transport of nitrite is easier than the parallel. This study highlighted the importance of choosing the most appropriate model depending on the objective to be achieved., The authors of this paper acknowledge the financial support from CONSOLIDER INGENIO 2010 (CSD2007-00016), Spain.

The production of safe and healthy food products represents one of the main objectives of the food industry. The presence of microorganisms in meat and products containing meat can result in a range of human health problems, as well as economic losses to producers of these products. However, contaminated meat products continue to initiate serious and large-scale outbreaks of disease in consumers. In addition to outbreaks of diseases caused by bacteria and viruses, parasitic organisms, such as Toxoplasma gondii, are responsible for foodborne infections worldwide, and in the case of T. gondii, is considered the 2nd leading cause of death from foodborne illness in the U.S. Transmission of Toxoplasma gondii has historically been linked to the consumption of raw or undercooked meat products, including pork. Specific concerns with respect to pork products are ready-to-eat (RTE) pork meals. These are pork or products containing pork that are prepared by curing or drying, and are not intended to be cooked before being consumed. Previous studies have demonstrated that T. gondii is inactivated during dry cured sausage preparation, apparently in the batter during fermentation. In this study, we have analyzed timing of inactivation of T. gondii in freshly prepared pepperoni batter to confirm our previous findings, to determine how quickly inactivation occurs during fermentation, and to confirm what parameters of the sausage preparation are involved in inactivation of the parasite. Results from the current and previous study indicate that rapid inactivation of T. gondii bradyzoites occurs in low salt batter for dry cured sausage within 4 h of initiation of fermentation., Highlights • Pork containing Toxoplasma bradyzoites was used to prepare dry cured pepperoni sausage. • A low salt (1.3%) formulation was used to prepare the pepperoni batter. • T. gondii was inactivated in pepperoni batter in

Cured meats are widely consumed in various regions of the world and, as for other foods, consumers are increasingly aware of the need for better quality and safety. Various fungal communities can colonise meat products during their curing with beneficial or detrimental effects depending on the dominant species. Some contribute to flavour, anti-oxidative and protective effects, while others cause spoilage, including undesirable off-flavours/odours and mycotoxin contamination. Recently, increasing research on fungal ecophysiology and mycotoxin occurrence, especially of ochratoxin A (OTA) and aflatoxins, has been shown in these products. This review addresses the existing and new knowledge which is available to provide insights into the reasons why certain fungi colonise cured meats including their ecology, the importance of critical control points and effective use of new monitoring methods for evaluating the risk of mycotoxin contamination of these products.

This chapter discloses results of an investigation concerning the performance of fly ash (FA)/waste glass alkaline-based mortars with recycled aggregates reinforced by hemp fibers exposed to accelerated carbon dioxide curing. Properties, freeze-thaw resistance, and carbon footprint of these mixtures with hemp were studied. The results show that is possible to develop FA-based mortars with relevant durability performance and negative carbon footprint.

Bioactive peptides derived from food matrices are currently a subject of intensive research, due to the multiple health benefits they can exert in the human body. However, the small size and low abundance of these peptides in complex matrices as well as the effect of food processing and gastrointestinal digestion on their structure, sequence, and functionality, are important challenges. Spanish dry-cured ham has been reported as a good and natural source of bioactive peptides mainly showing antihypertensive and antioxidant activities. In this work, the antioxidant peptide AEEEYPDL, identified from 9 months of curing dry-cured ham, showed good resistance to different heat treatments and salt contents. The bioactivity of the peptide significantly decreased after simulated gastrointestinal digestion. An optimised multiple reaction monitoring methodology was able to quantify the peptide AEEEYPDL at a concentration of 0.148 fg per g of dry-cured ham, despite the existing challenges in the quantification of bioactive peptides from complex matrices., Grant AGL2014-57367-R and FEDER funds from the Spanish Ministry of Economy, Industry and Competitiveness are acknowledged. Juan de la Cierva de Incorporación postdoctoral contract to LM is also acknowledged.

The objective of this study was to investigate the effect of ultrasonic frequencies and drying time on fatty acid profiles of beef jerky samples possessing different microbial compositions. Beef slices were cured using curing solutions formulated both with and without Lactobacillus sakei . Curing was carried out for 18 h at 4 °C prior to hot air drying at 60 °C for 4 h. Jerky samples from both treatment groups were then subjected to ultrasonic frequencies of 25 kHz, 33 kHz and 45 kHz for 30 min. Beef jerky samples were subsequently analysed for fatty acid profile using Gas Chromatography. In the present study, beef slices showed a high level of MUFAs, which accounted for 45.6–53.8%, followed by the SFAs (36.3–47.8%) and PUFAs (4.8–13.7%), respectively. Results demonstrated a significant effect of beef jerky processing on fatty acid profile. Various correlation analyses showed that changes in fatty acid profiles were significantly affected by individual and/or interactive effects of L. sakei , drying time and ultrasonic frequency.

[EN] Online ultrasound measurements were taken using pulse-echo mode in loins (Longissimus dorsi) and hams at different salting times (up to 30 days). From the time-domain ultrasonic wave, the time of flight (TOF) was computed as well as its variation between two signals (Delta TOF). A progressive decrease in TOF during dry salting was found, which was linked to the salt gain, water loss and the reduction in sample thickness. Predictive models based on the ultrasonic parameters (Delta TOF and initial time of flight, TOF0) correctly classified 85% of the loins and 90% of the hams into 3 groups of salt content (low/medium/high): The results obtained confirm that the use of the ultrasonic pulse-echo technique is of great potential in the non-destructive monitoring of dry salting in pork loins and hams, as well as in the prediction of the salt gain for classification purposes. (C) 2017 Elsevier Ltd. All rights reserved., This work was supported by the Spanish Ministerio de Economia y Competitividad (MINECO), the Instituto Nacional de Investigation y Tecnologia Agraria y Alimentaria (INIA) and the European Regional Development Fund (ERDF 2014-2020) (contract n. RTA2013-00030-C03-02), by the PROMETEOII\2014\005 and by the Universitat Politecnica de Valencia (UPV) through the FPI grant awarded to Marta de Prados (SP-1.2011-S1-2757)

[EN] The effect of the direction of the meat fiber on the diffusion of sodium nitrate and water in Semimembranosus pork muscle during curing was studied at different temperatures. Nitrate and water diffusion were modelled based on Fick's second law. The nitrate diffusion coefficients ranged from 0.007·10¿10 to 0.034·10¿10 m2/s (parallel) and 0.89·10¿10 to 1.41·10¿10 m2/s (perpendicular), while for water the values ranged from 9.87·10¿9 to 12.46·10¿9 m2/s (parallel) and 5.22·10¿10 to 9.29·10¿10 m2/s (perpendicular). In every case, these values increased as the temperature rose. The activation energy for water diffusion perpendicular to the meat fiber (31.86 kJ/mol) was greater than when the diffusion was parallel (15.06 kJ/mol). The opposite was observed for nitrate diffusion (96.44 kJ/mol when parallel vs. 24.71 kJ/mol when perpendicular), which implies that nitrate needs more energy for parallel diffusion and, consequently, curing is slower in that direction., The authors of this paper acknowledge the financial support from Spanish Government ("Ministerio de Educacion y Cultura", CONSOLIDER INGENIO 2010, CSD2007-00016) and from the Valencian Government ("Generalitat Valenciana", Valencia, Spain, PROMETEOII/2014/0005).

Meat flavor is affected by the major precursors, proteins, and lipids. In this chapter the main reactions involved in the development of cooked meat aroma are fully described: lipid degradation, Maillard reactions, Strecker degradation, thiamine degradation, and carbohydrate degradation. In addition, the different isolation and identification techniques used for flavor characterization of the volatile compounds present in meat are described together with techniques used for evaluation of potent odorants such as odor activity value and olfactometry analysis. The aroma compounds in cooked meat from different animal species have been summarized together with those pre- and postslaughter factors affecting it. The antemortem factors are age, breed, sex, fat level, fat profile, and composition while postmortem factors are aging, cooking, storage after cooking, and the development of off-flavors due to irradiation and storage. Finally, the development of meat product flavor through wet and dry curing is explained and the main aroma compounds defined.

Cooked ham is a cured product typically derived from the hind legs of swine, which is preserved through processes like cooking and, optionally, smoking. Ham products can also be manufactured using non-leg muscles. The processing of cooked ham involves the use of brine that is either injected or soaked, followed by the application of thermal treatment. The piece of ham may be either entire with bones in or deboned before cooking. The consumption of cooked ham is quite relevant in many countries worldwide. The processing technologies for the production of cooked ham may change depending on the raw materials and the processing conditions utilized.

Curing is among the most ancient preservation technologies for foodstuffs; it involves the addition of salt together with nitrate or nitrite. The technological value of this processing is unquestionable, since it helps to create a stable red/pink color in meat products, shows a protective role in oxidative reactions of lipids and proteins, improves the flavor of products, and, even more importantly, exhibits a very unique antimicrobial effect on Clostridium botulinum . However, the potential implication of nitrates and nitrites in the formation of carcinogenic N -nitroso compounds, both in the food and in the human body, has led to a worldwide debate about the allowance of nitrate/nitrite use.