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As the world faces a growing problem of freshwater scarcity, the construction industry—which as a sector is among the largest consumers of freshwater globally, especially for concrete mixing, curing and cleaning must consider alternatives that can help solve the issues associated with water shortages while continuing to meet the construction industry’s essential needs. In many cases, the same regions experiencing severe water shortages are in relatively close proximity to the sea or ocean; in these areas, the concrete industry potentially has access to a practically unlimited source of water which is currently not widely viewed as a viable option. Although the use of seawater in concrete can result in some minor changes in its fresh and hardened properties, one of the main long-term challenges is related to the high concentration of chlorides which leads to depassivation of reinforcing steel and results in corrosion-induced deterioration. Therefore, a corrosion-resistant reinforcing material, such as fiber-reinforced polymer (FRP) bars, may provide an acceptable alternative for concrete structures when non-potable mixing water is used. The present research is part of a broader study exploring the viability of seawater concrete structures reinforced with glass FRP (GFRP) bars. In this work, an experimental program comprised of six beam anchorage specimens reinforced with 16 mm spiral GFRP bars were tested. Three control beams were fabricated using concrete made with regular tap water, while the remaining beams used concrete made with seawater. The embedment length of the GFRP bars in the anchorage regions ranged from 300 to 500 mm. A method is proposed for calibrating theoretical bond-slip relationships using strain readings along the embedded region. Using the calibrated model, the development length of the bars is estimated and compared with current design codes which were found to be conservative. The results of this study, in combination with other results not presented here, suggest that the use of seawater as mixing water in concrete has a negligible effect on the bond behavior and overall structural performance of GFRP-reinforced concrete elements. Further research on long-term performance is ongoing.

The paper presents the results of an experimental investigation of the kinetics of internal stresses in aqueous and UV aqueous varnish films formed on a solid substrate. Internal stresses occur as a result of volume change during the curing and adhesion period of the film and substrate . The cantilever method was used for the analysis of internal stresses. This method is based on the principle of a clamped thin elastic narrow plate at one end. The influence of film thickness as well as the kinetics of internal stresses were controlled. In the kinetics of internal stresses of the investigated water varnish, a period in which internal stresses do not occur at the beginning of drying, a period of occurrence of internal stresses and their intensive growth, a period of decreasing intensity of internal stresses to maximum and a period of retention at the achieved level can be observed.

Nowadays, High-performance concrete (HPC) has been used to gradually alternative ordinary conventional concrete for structures exposed to harsh environments to improve the long-term durability of concrete. The principal aim of this research was to utilize industrial waste by-products like fly ash, silica fume as an addition to cement at different rates incorporating quartz powder in HPC mixes for application in concrete structures subjected to severe environmental conditions. The corrosion resistance of HPC was examined by the mass and compressive strength loss of 15 × 15 × 15 cm3 cubes immersed in seawater and saline-alkaline environments. The result experimental indicates that an optimum mixture could be achieved with the use of 12.5% SF, 20% FA for cement substitution, and 20% Qp substitute sand. The compressive strengths of all mixes curing in potable-water obtained varies between 70.76 and 91.15 MPa at 28th days, these values gained 78.1 to 101.6 MPa at 540th days. Compared to cubes immersed in freshwater, similar compressive strength values have been received reduced from 0.13 to 2.78% strength for seawater environment, whereas exposed to saline-alkaline medium has decreased from 0.13 to 2.78% and mass loss ranges from 0.11 to 2.1% of specimens, after curing period 540 days. It is observed that the HPC produced with locally available materials in Vietnam proved its excellent mechanical and durability properties. In the future, HPC will be used vastly in the construction industry, as well as for concrete structures exposed to synthetic corrosive medium similar to Vietnam.

Cold recycling of reclaimed asphalt (RA) is a promising technique to build or to maintain roads, combining performance and environmental advantages. Although this technique has been extensively used worldwide, there is no unique and internationally-shared method to characterize cold recycled mixtures. The previous work of the RILEM TC 237-SIB TG6 successfully attempted to characterize different RA sources with both traditional parameters (gradation, bitumen content and geometrical properties) and non-conventional properties (fragmentation and strength testing). The current RILEM TC 264-RAP TG1 mainly focuses on the influence of different RA sources on physical and mechanical characteristics of cement-bitumen treated materials (CBTM) using foam or emulsified bitumen, taking into consideration compaction and curing methods. This paper presents results from the first step of the inter-laboratory project in which foamed bitumen and cement were used as binders. The influence of two RA sources, one from Alabama (USA) and one from San Marino, were investigated through the collaboration of several laboratories. Specimens were manufactured with the same diameter by means of both Marshall and gyratory compactors and then cured following two procedures: free surface drying (FSD) and partially-surface drying (PSD). A preliminary study allowed obtaining specimens with similar volumetric properties. Along with compactability and water loss, the indirect tensile stiffness modulus was measured and analyzed. The results have shown that the RA source and curing procedure influence the CBTM mechanical properties.

Cold in-place recycling is a commonly used maintenance treatment in rehabilitation of low and medium volume roads in Poland. Typically, two types of binding agents are used—cement and bituminous emulsion (or foamed bitumen).Due to the harsh Polish climate with many freeze/thaw cycles and frequent occurrence of saturated conditions, the used amounts of cement are higher than those commonly used in warmer parts of Europe. While there is usually only one type of bituminous emulsion dedicated for cold recycling on the market, there are numerous types of cements, which differ in chemical composition and properties. The conducted research presents possible development of cold recycled mixture properties over curing time, taking into account the type of cement used. Two types of cement were tested in laboratory investigation—common Portland CEM I 32.5 R cement and Portland-fly ash CEM II 32.5 B-V cement with longer setting time. Cold recycled mixtures were designed with the same composition and amount of binding agents, but differed in the type of cement used. For both mixtures, indirect tensile strength and modulus were tested after 7, 28 and 90 days of curing in laboratory conditions. The laboratory tests confirmed lower values of strength and modulus for the fly ash cement after 7 and 28 days in comparison to the typical cement, but after 90 days the properties of both tested mixtures presented similar values. If the overall predicted fatigue life and long-term mechanical properties are the same, the use of slow-setting cementsmay result in reduction of reflective cracking on the surface of the pavement. In the case of low and medium volume roads, where there is no need for fast paving of the asphalt layers and more time may be allowed for the cold-recycled mixture to achieve the required initial strength, slow-setting cements should be considered as a viable treatment for reduction of the risk of reflective cracking.

The objective of this research study is to evaluate both laboratory and field performance of Cold In-Place Recycling (CIR) asphalt mixtures in terms of rutting and cracking resistance. A balanced CIR mixture prepared with foamed asphalt at 2.5% foaming water was selected to construct three full-scale CIR sections at Rowan University’s Accelerated Pavement Testing Facility (RUAPTF): (1) a rut-resistant section (i.e., containing 2% binder content), (2) a crack-resistant section (i.e., containing 4% binder content), and (3) a performance-based section (i.e., containing 3% binder content). Once cured, one inch Hot Mix Asphalt (HMA) was placed on top of the CIR Layer. An accelerated pavement testing (APT) was then performed on each section using Dynatest Mark IV Heavy Vehicle Simulator (HVS) to apply repeated truck tire loading magnitudes for 150,000 passes. Pavement mechanistic responses were recorded by asphalt strain gauges, pressure cells, and thermocouples embedded at the bottom of each CIR layer. Rutting and cracking performance of each section was assessed and compared to the laboratory performance of foamed asphalt CIR mixtures compacted with 30 gyrations and subjected to a three-day curing at 10 °C. The results showed that the rut-resistant section presented lower rutting susceptibility, while all three section showed a similar cracking resistance under accelerated truck loading.

To investigate the behavior of an emulsified asphalt mix during curing, the mechanical behavior and water loss of the material were studied in laboratory. The mechanical behavior of the mix was evaluated using the oedometric modulus. The dependence of the material to seasonal curing was highlighted obtaining higher stiffness values for warm conditions rather than cold ones. The influence of the water content was also observed through the temporary decrease of modulus during induced peaks of humidity. However it is concluded that the decrease of water content during curing is not sufficient by itself to account for the behavior of emulsified asphalt mixes since they continue to evolve even after full drying.

Class F fly ash is an integral component of most Strain Hardening Cementitious Composites (SHCCs). It reacts with the calcium hydroxide produced in the primary hydration of cement. As calcium hydroxide disintegrates at lower temperatures than other cement hydration products, reducing it through the pozzolanic reaction with fly ash has been shown to improve the thermal stability of SHCC. However, the degree (or extent) of the pozzolanic reaction increases with curing age. Therefore, the effects of fly ash content on the residual compressive strength of SHCC after exposure to elevated temperatures must be investigated at different curing ages, which is the motivation behind this study. Three different SHCCs with fly/ash to cement (FA/c) weight ratios of 1.2, 2.4, and 3.6 were tested at 28 days and 150 days under residual conditions after being subjected to high temperatures of up to 600 °C. The results show that the beneficial effects of high FA/c ratios on the residual compressive strength, associated with the accelerated pozzolanic reaction of fly ash at high temperatures, are lost at the long curing age.

The concept of sustainability from conception of a project to its completion has become a priority in the civil engineering industry in which there is an acute scarcity of materials due to depletion of natural resources as ingredients of concrete. Self-Compacting Concrete (SCC), proposed in 1989 by Prof. Okamura of Japan, for the first time, had revolutionized the process of placing concrete by eliminating the compaction. SCC, a self-flowing concrete possesses flowability whilst maintaining stability/homogeneity without segregation; thus allowing filling up of congested areas in concrete between the bars in congested reinforcement. The flowability obtained from the use of high-range water-reducing admixtures helps in achieving better packing of concrete around reinforcements and superior quality surface finishes. The mineral admixtures such as Fly Ash, GGBS etc., added as powder content enhance resistance to segregation, reduce the cost of production and improve micro-structure of SCC. The experimental study focuses on the assessment of fresh properties of SCC with an equal blend of three cementitious materials; namely cement, fly ash and GGBS called Triple Blend SCC (TBSCC). The mix proportion is designed by Absolute Volume method. The conventional/control SCC mix consists of cement (70%) and fly ash (30%) with natural river sand as fine aggregates. The properties of SCC are controlled by the characteristics of materials and the mix proportions. The properties of different constituent materials used for SCC are assessed as per the standard tests procedures. The acceptance criteria in the fresh state of SCC are assessed through slump flow, V-funnel and L-Box as per EFNARC 2005. The improvement in rheology of SCC mixes and enhancement of compressive strength at 28 days curing period may be attributed to usage of three mineral admixtures in equal proportion. This practice of triple blend cementitious content in SCC advocates the reduction of 67% cement content in SCC with improved fresh properties and strength of SCC, thus producing a sustainable solution for the filed applications.

Curing of bricks during manufacturing process and construction work has a significant impact on the strength, durability and wear resistance of concrete. If the concrete is not properly and adequately cured, it will fail to satisfy the purpose for which it is designed. Minimum 12–24 days curing is required for bricks during the manufacturing process and minimum 7 days water supply is required for masonry wall and concrete. Bricks require a lot of water and time for curing. Maximum use of water is an environmental issue and supply of water by laborers from tube wells to construction sites has an adverse impact on their health. In the present work we have developed two methods for curing bricks and concrete. First method will help for curing of bricks and concrete during the manufacturing process without the requirement of a single drop of water and the second method will help for better supply of water to constructional workplaces with minimum effort.

Geopolymer has been considered a popular alternative to traditional cement. Materials which are rich in silica and alumina can be used along with traditional aggregates to prepare geopolymer mortar and masonry units. This chapter deals with the development of geopolymer masonry units such as brick (GPB), solid block (GPSB) and hollow block (GPHB). All these products were tested for dimensionality, water absorption, strength, modulus of elasticity, etc. They possessed better properties compared to traditional masonry units. The same units were used for making masonry prisms, and wallets. The prisms and wallets were loaded with axial and eccentric loads and tested for compression. The modulus of elasticity was also determined along with the crack pattern. Results indicated that the prisms and wallets performed exceedingly well compared to the traditional masonry structures. Moreover, no traditional cement is required in any stage of construction. The traditional water curing and thermal input is avoided. Based on this study, geopolymer masonry units are strongly recommended for the structural masonry without compromising properties.

Lime has been used as the most sustainable binder for the conservation and restoration of heritage buildings. The repair properties of lime based mortars are found superior to other mortars due to the compatibility issues of other mortars with ancient heritage structures. To increase the compatibility, the fresh lime mortar needs to be hardened by carbonation which is a slow process. Various researches showed that admixtures added advantage to lime mortar by increasing carbonation rate which increases the mechanical strength, weather and water resistance of the lime mortar. In India, plants, fruits and some part of vegetables were used as organic admixtures that increased the carbonation rate thereby promoting sustainable and eco-friendly repair mortar. This paper deals with how the slaking of lime putty with organic additives affect the carbonation and other properties of the repair mortar. To enhance the carbonation rate, organic was mixed with water and this organic water was added for slaking the lime putty. Raisins were added as the organic additive at an amount of 0, 2, 4 and 6 percentages. The process was monitored for a month and cubes were casted. Compressive strength test was performed to measure the mechanical resistance property of lime mortar. Analytical tests such as XRD analysis and FT-IR were performed to determine the chemical compatibility after curing it for 90 days. It was seen that the carbonation rate and the mechanical strength of lime was greatly influenced by the organic water slaked lime mortar.

This work presents the results of the measurements carried out by the Laboratory of Archaeological and Building Materials of NCSR “Demokritos” in the framework of the Interlaboratory Test (ILT) organized by SARCOS COST action CA15202. The overall aim of ILT was to assess the self-healing properties of concrete with the addition of a self-healing agent. Following the ILT tentative methodology, the concrete samples were initially subjected to controlled cracking after curing for 30 days. Their sealing efficiency−as part of the self-healing process−were assessed by water permeability tests carried out in disk specimens cured for 1, 3 and 6 months under water, as a healing regime. At the same time, crack width of all samples was measured each time, by examination at the stereomicroscope. Besides the measurements regarding the sealing efficiency, Scanning Electron Microscopy (SEM) was also performed, in order to understand the contribution of the healing agent on the sealing mechanism. In this context, samples were collected from the crack face and the secondary healing products inside the cracks were studied by SEM combined with X-ray spectroscopy (EDS) in samples with and without the healing agent. The interpretation of the results suggests that the main methodological parameter affecting the sealing efficiency is the initial crack width. This indicates that during the quantitative evaluation of the sealing results, the initial level of damage attributed to the specimens should always be considered. In addition, SEM examination revealed the composition and the morphology of the healing products that were identified in the fractured surfaces and thus, the relative contribution of both healing agent and cement hydration.

The objective of this research was to evaluate the performance of concrete containing recycled aggregates of different sizes and replacement percentages. Mixtures were prepared using a combination of natural and recycled aggregates. The recycled aggregates were treated in a concrete mixer truck to partially remove the adhered cement paste in order to compare their performance in concrete as opposed to natural aggregates and non-treated recycled aggregates. One high-strength concrete series of mixtures was prepared to employ the concept of internal curing. The mixtures were tested for their mechanical properties and durability. The results showed that the addition of recycled aggregates in concrete up to a specific replacement percentage did not adversely affect the concrete properties. The specific research suggests that recycled aggregates can be a very good alternative source to reduce natural aggregates consumption and utilize waste material.

The positive influence of longer duration of wet curing in improving the mechanical and durability properties of concrete is fairly well established. However, it is increasingly becoming apparent that longer duration of wet curing, unfavorably affects the drying shrinkage characteristics of concrete, resulting in both increased amount of shrinkage and also increased cracking potential under restrained conditions. Various types of fibers have been developed and used to enhance the durability of concrete structures by controlling the restrained shrinkage cracking. However, the influence of longer duration of wet curing on the age at cracking and crack characteristics of concrete containing macro polymeric fibers has not been previously determined. In this research, the effects of three different curing durations on strength characteristics and free and restrained drying shrinkage performance of mixes with and without macro polymeric fibers were studied. The results show that drying shrinkage and cracking potential of the control mixes increased with longer duration of wet curing, confirming the trend reported by recent literature. Interestingly the mixes containing fibers also showed the same trend and both the amount of free shrinkage and the restrained shrinkage potential increased with increased duration of wet curing. With regards to crack widths, the results show that with longer wet curing, the width of the single crack for the control mixes increased significantly while the cumulative width of the multiple cracks of the mixes with polymeric fibers increased only modestly.

Study into the compressive strength of revibrated concrete using smart combination of sawdust ash from selected wood species to partially replace cement is presented. Apa and mahogany wood species were used to carry out this study. Chemical analysis of the ASDA and MSDA contain the major chemical oxides found in cement which includes SiO2, Al2O3 and Fe2O3. Six (6) concrete cubes of 0% replacement by weight were produced with ordinary Portland cement (OPC), while another Six (6) concrete cubes were cast each using 5, 10, 15, 20, 25 and 30% replacement of OPC with SDA from the specified wood species giving rise to a total of fifty-six (56) cubes produced without revibration. These cubes were cured and subjected to a compressive strength test at 7 and 28 days. The optimum ASDA replacement for cement was attained at 5%, while that of concrete cube containing MSDA was attained at 10%. Another set of concrete cubes numbering eighty-four (84) was produced, fifty-six (56) of which were cast using the optimum percentage from ASDA and MSDA, while the remaining twenty-eight (28) were cast using OPC only. All the eighty-four cubes were revibrated for 1 min 20 s at 10 min intervals to a duration of 1 h after initial vibration. The cubes were cured for 7 days, 28 days and subjected to compressive strength test. The result reveals that the compressive strength of the revibrated concrete cubes increases up to a certain time lag and thereafter decreases to the lap hour of 1 h. The result also reveals that the percentage increase in compressive strength value obtained after revibration for a curing period of 7 and 28 days using 0% (only OPC) increased by 28.01 and 37.31%, that of the 5% ASDA optimum percentage replacement obtained increased by 48.40 and 40.49% and also that of 10% MSDA optimum percentage replacement obtained increased by 33.58 and 40.83% compared to the average value obtained for the corresponding percentage replacement for the non-revibrated concrete cubes. Hence, the study suggests that re-vibration enhances the strength of concrete once done within the plastic stage of the concrete.

This paper comprises the enhanced self-healing properties of fiber-reinforced cementitious composites by taking advantage of synergistic effect of using different mineral admixtures. To do this, single and binary use of metakaolin (MK) and zeolite (Z) were utilized in cement-based mixtures, and early age self-healing behavior of specimens was assessed based on sorptivity tests. The autogenous self-healing performance of each mixture was also evaluated via crack width assessments by using a video microscope. Results were compared with the sound and preloaded specimens having different crack width levels. In addition, mechanical properties of four different mixtures were evaluated by conducting experiments on 7 and 28 days. The multiple crack width closures and sorptivity coefficients of preloaded specimens indicated that an effective combination of MK and Z can trigger a higher level of self-healing in comparison with reference mixture. However, single-use of Z in mixtures was also promising for achieving autogenous self-healing attributes compared to mixtures containing only MK and to reference mixtures. Having said that, this behavior should also be addressed for different pre-cracking and prolonged curing age of each mixture.

Rock aggregates are major construction materials globally. However, high cost, scarcity, environmental problems, and depletion of natural resources associated with the production of crushed rocks for subbase and base courses have necessitated search for alternative available quality materials for sustainable highway pavement construction. Cement was added to lateritic soils at varying percentages of 2, 4, 6, 8, and 10%. The soil–cements were subjected to various laboratory tests to establish their potentials for use as pavement layers instead of crushed rocks for economical and environmental sustainability. In addition, CBR, UCS of the soil–cements (cured for 7 and 14 days), and the percentage of cement model were used to establish a second-order polynomial to correlate the soil–cement mix. Compaction results showed a decrease in maximum dry density and an increase in optimum moisture content. California bearing ratio (unsoaked CBR and soaked CBR) and unconfined compressive strength (UCS) values of the cement-stabilized lateritic soils cured for 7 and 14 days increased with higher cement contents up to 8%, after which there were reductions in CBR and UCS. The strength of the soils does not only depend on cement content, but also on the soil curing period. The obtained improved strength indices allow a reduction in the pavement thickness at a low cost of road construction. The polynomial model was found to predict good relationships between strength indices and the percentage of the cement used. 8% by the soil weight of the cement. The stabilized lateritic soils could be used as potential subbase and base materials for highway construction.

Sustainable development becomes necessary to protect our existing environmental conditions. The agricultural and metal industry produces various residues which are having prospective tobe utilized as a supplementary for the cement. Rice husk ash (RHA) minimizes the carbon footprints emissions and achieves green effect in the existing environment. Ground Granulated Blast Furnace Slag (GGBS) is utilized as an alternative to the cement which helps in reducing CO2 emissions and minimizes the consumption of non-renewable resources of lime stone. The corresponding study insights the usage of supplementary materials like GGBS and RHA into the production of concrete matrix. Also, the aim of this study is to achieve sustainable development incorporating the agricultural and industrial wastes into concrete industry, which can be beneficial for the nation and loss the effect on natural ingredients on convectional concrete. The present study is carried out to optimize percentages of RHA and GGBS after the replacement to the cement such as 0, 5, 10, 15, 20, 25 and, 30% interval. Also, to evaluate the compression and split-tensile strength of conventional concrete with different ages of 7 and 28 days under normal curing conditions. The prediction model for compression strength is prepared using statistical analysis.

Liquid membrane-forming compound curing is a type of water retaining curing concrete technique by forming a membrane on the surface of the concrete. This study aimed to investigate the effectiveness of liquid membrane – forming concrete curing compounds produced in Ethiopia. The methodology include compressive strength and water absorption (on C-25 and C-40 grades of concrete) for samples examined under laboratory conditions and by exposing samples to external weather conditions which were cured through curing compounds, water sprinkling and plastic sheet covering. Additionally drying time and deleterious reaction tests were carried out. Liquid membrane – forming concrete curing compounds produced in Ethiopia are effective in compressive strength but not in water absorption, which water absorption was used to measure concrete quality in this study. Water sprinkling and plastic sheet covering methods were effective in compressive strength and water absorption than curing compounds. Regarding cost comparisons, water sprinkling method of curing is less costly than curing compounds and burlap coverings, and curing compound is more costly than the two.

A significant amount of mineral wool waste is generated during the construction and demolition of buildings. At the moment, most of this material ends up in a landfill without further utilization. Alkali activation is one technology already recognized to produce low carbon dioxide binders and other products/materials from several industrial by-products, and could also be employed to recycle mineral wool waste. This study shows the result of milling and homogenization of different types of wool waste and their subsequent use as precursors in the alkali-activation process. Two different types of mineral wool waste were taken from the mining company Termit (Slovenia). Stone and glass wool were milled, pulverized and sieved below 63 μm. After homogenization, different alkali-activated pastes were prepared using two different alkali activators (NaOH and/or Na–water glass). The compressive and flexural strength of each alkali-activated material was measured, showing higher values for glass wool in comparison to stone wool. In addition, different curing temperatures were assessed (room temperature and 40 °C). The compressive and flexural strength of glass wool after three days at 40 °C was 34.7 and 8.7 MPa respectively, compared to values of 29.1 and 9.3 MPa for stone wool. After 3 days at room temperature, the strengths were not measurable, however, after 28 days the respective compressive and flexural strength were 29.9 and 14.4 MPa in the case of glass wool, and 40.6 and 14.9 MPa for stone wool.

Hybrid cements (cements composed of Portland clinker, supplementary cementitious materials and an alkaline activator) potentially combine advantages of conventional cements with those of alternative binders, such as low heat of hydration and improved durability in some environments. While fly ash-based hybrid cements have been studied in considerable detail, slag-dominated hybrid cements appear to have received less attention. Here, the latter materials have been studied by isothermal calorimetry, X-ray diffraction and strength testing. The heat of hydration of these cements was as low as ~50% of that of an ordinary Portland cement, while their strength after 28-day curing was in the range 31–61 MPa. The phase assemblages after 28-day curing depended on the activator, with Na2SO4 leading to ettringite and Na2CO3 leading to hemicarbonate formation, respectively, besides C–A–S–H, portlandite and hydrotalcite. The U phase was identified when a high Na2SO4 dose and/or fly ash was employed. Na2SO4 accelerated the early reaction of the Portland clinker, while Na2CO3 appeared to decrease the extent of reaction of the clinker and led to a shift of the second hydration peak (likely related to slag reaction) to later hydration times, as did substitution of slag by fly ash. Increasing Na2SO4 dose from 4 to 6% did not lead to further acceleration of hydration or improved strength.

The purpose of this study was to evaluate the environmental impact of the use of harbour dredging sediments (HDS) from active lagooning in the formulation of self-compacting concrete (SCC). Concerning the beneficial use of sediments as alternative granular material in construction, the developed experimental methodology allows to incorporate a more optimized content of sediments in cementitious materials than the current experimental approaches. The studied sediments do not undergo any chemical or thermal treatment. The DMDA (Densified Mixture Design Algorithm) method was used to formulate cementitious materials and optimize the sediment content. The paper focused on mortars equivalent to these “sediments” (SCMs). The experimental program considered three different HDS with three different fines rates at 125 μm. Considering the environmental regulation context, the studied HDSs are classified as non-hazardous waste with reference to the European Directive 1999/31/EC—Decision 2003/33/EC. Heavy metals contained in sediments were stabilized with the cementitious matrix, except nickel. In particular, a notable decrease in barium and chloride concentrations was observed. The different mortars are classified as inert, the clinker hydration producing hydrates that capture and stabilize heavy metals in the cementitious matrix. After a 28-day curing period in water at 20 ℃, a C25/30 mechanical class concrete was obtained. The obtained experimental results show that raw HDS from active lagooning has a real potential to be used as a secondary raw material with the incorporated notable quantity in the SCC formulation.

This article presents an experimental study on the application of processed biochar as a partial replacement of cement. Raw biochar was chemo-mechanically modified to produce super-hydrophobic carbonaceous powder (SHCP). The effects of this SHCP on paste and mortar samples were monitored in terms of compressive strength, hydration products, electrical conductivity, water absorption, and embodied carbon. The performances of the mortar samples were monitored after 7 and 28 days of sealed curing. SHCP primarily worked as inert inclusion and did not significantly affect the cement hydration. Nevertheless, the addition of SHCP as partial replacement of cement was found to decrease the water sorption, increase the electrical conductivity, and decrease the embodied carbon of the mortar samples. As such, this study provided experimental evidence that biochar can be utilized as a multifunctional additive in cement-based composites.

Cement production and its use need to be controlled but not at the cost of halting the current pace of industrialization. Alternatives for cement are constantly being worked out. Flyash has evolved as a novel construction material which has huge potential to replace cement and manufacture cementless concrete. It is termed as geopolymer concrete. In present investigation, for preparing M45 grade concrete, Sodium silicate solution with Na2O = 16.57%, SiO2 = 34.25% and H2O = 49.18% and sodium hydroxide solution having 16Mconcentration were maintained constant throughout the experiment. Water-to-geopolymer binder ratio of 0.2, alkaline solution-to-fly ash ratio of 0.35 and sodium silicate-to-sodium hydroxide ratio of 2.5 by mass was fixed based on workability and cube compressive strength. Wet curing applied by immersing specimen in water and room temperature curing applied by keeping specimen at laboratory room temperature for specified time period and tested further. It is observed that the results of workability and compressive strength are well-matched with the required degree of workability and compressive strength. So, the proposed method is used to design normal and standard geopolymer concrete.

The desire to accelerate adhesive application processes drives the development of rapid curing adhesives. When selecting a certain adhesive for an application, typically a variety of tests is performed in order to characterize its properties. Especially, the mechanical properties and their development under different heating conditions are of interest. Commonly used analytical methods only provide limit information for rapid curing adhesives. This motivates the development of a new experimental setup enabling rheological measurements at high heating rates. This contribution defines requirements for such a novel setup. Induction heating is chosen to facilitate rapid temperature increase. Further, different materials are evaluated for their heating performance and their use for measurement components. A real-time capable temperature control is enabled due to the selected temperature sensor types and positioning. This study develops the design of heating units which can be mounted on a modern rheometer. Additionally, the impact of rapid heating on the measurement accuracy is investigated. Two major factors are identified: the influence of rapid temperature increase on the thermal expansion of the measurement geometry and on the torsional compliance.

The paper investigates the heat formation and absorption processes in the cement-water system. The temperature gradient in a cement composition is one of the mainsprings of cement hydration and curing and the formation of final properties of the cement-water system. The differential calorimetric analysis based on measuring the temperature difference between dry and wet cement shows the reciprocal, cyclic heat formation. The observed effects are caused by the processes of dispersion and hydration of cement particles and crystallization of cement hydration products. Three types of harmonic frequencies are detected for the heat formation, viz. 1–3 vibrations per minute, ~12 h, and a several days vibration period. The heat formation-based analysis of phenomena observed in the cement-water system shows self-excited vibrations during the cement hydration and curing. The reaction continues owing to the energy release during hydration of clinker minerals and dispersion of the initial cement particles. The high sensitivity of the differential calorimetry as against the integral methods provides the deeper understanding of the phenomena observed and allows improving the cement potential in the production of a wide range of building materials.

Concrete incorporates a natural self-healing capability that is primarily created by hydration and carbonation to repair small cracks. This ability is limited and is only activated when direct contact with water takes place. The study mainly dealt with crack repair and sustainability. For the repair of cracks, autogenous healing mechanism is adopted. Autogenous healing can be accelerated by the addition of mineral additives. The mineral additive used for autogenous healing is metakaolin. The use of metakaolin in high performance concrete can improve both the strength and durability properties of concrete. The ability of autogenous self-healing will increase with higher cement content. The experiment was conducted on high performance concrete of M70 grade. 10% replacement of cement with metakaolin is considered for the study. Specimens with addition of metakaolin and without metakaolin were subjected to 0 day, 3 days and 7 days curing. This study mainly focused on the strength retained, type of crack formed, propagation of cracks and amount of crack healed. The compressive strength and flexural strength at 7 day, 28 day and 180 days were carried out. Flexural strength test carried on beam specimens of size 700 × 150 × 150 mm was subjected to two-point loading. It has been observed that the specimens with metakaolin gives increased compressive and flexural strength than those specimens without adding metakaolin. The early age cracks in concrete structure will get reduced due to the addition of metakaolin. Also the addition of metakaolin promoted autogenous self-healing.

Globally, the pressure mounts towards attaining low carbon emissions in the energy sector, which has propelled the G8 Summit to advocate for radical high technology approaches for cement production. Among the modern technologies recommended, which also offers the techno-economic advantages is the microwave-based curing. Low pressure accelerated microwave heating, also called accelerated dewatering, is an innovative technique that enhances the properties of HSCP. This study has analyzed the effect of this improvement including the impact of the pressure on feed direction, MW cavity, and the different HSPC samples for every MW treatment batch. The initial state of this treatment established the following. First, to evade internal structure cracks, the delay time should precede the setting time (averagely 30 min after mixing). Secondly, the moisture and temperature increase differences within the MW cavity should be minimal. By following low-pressure microwave treatment will significantly improve properties of HSCP by increasing the resistance to drying shrinkage and water permeability.

Geopolymers, a class of largely amorphous aluminosilicate binder materials, have been extensively studied over the several past decades. New metakaolin-based geopolymer formulations were elaborated by addition of lamp waste glass and with sodium silicate/NaOH activation. The influence on the microstructure and mechanical properties of compositional variation with partial replacement of metakaolin by lamp waste glass (0, 25, 50, and 75%) and Si/Al ratio (3.5 and 4) were studied. From 1 to 7 days of curing, the combination of these two amorphous materials (metakaolin and glass) exhibited suitable compressive strength values reaching 17 MPa. At higher Si/Al ratio (3.5–4), these values are largely superior to metakaolin-based one (around 4 MPa). At higher percentage of waste (25% metakaolin, 75% glass), the mechanical resistance tends to decrease due to the higher reactivity of metakaolin with alkaline solution. This behavior is also observed when more curing time is applied to the studied geopolymers (28 days).

Internal curing using fine lightweight aggregate is an effective method to address early-age cracking. This study focuses on the sustainability of using fine lightweight aggregates for internally curing concrete. Application of fine lightweight aggregates has a positive influence on transport properties of concrete and enhances the durability and service life of concrete infrastructure. These properties contribute to the performance of those infrastructures in various environments and climate zones. This paper highlights the sustainability of internal curing application through cost, energy, and emission analyses based on existing service life prediction models and using transport properties of internally-cured concrete obtained through experimental investigations. Presented methodology covers data acquisition and refinement procedures to perform such analyses. Analysis includes a range of concrete applications to simulate current trends in concrete market. Results highlight quantitative sustainability performance measures, such as energy and emissions in addition to cost and time for selected applications in parking structures and bridge decks.

Traditional concrete materials are prone to cracking and as cracks form, durability issues arise which reduce the expected service life of the materials followed by structures incorporating them. This, in many occasions, may lead to repetitive repair and maintenance or even re-construction of certain structural/non-structural sections and structures. Thus, it is highly desirable to reduce the chance and/or further development of cracking. Engineered Cementitious Composites (ECC) are feasible materials to suppress cracking formation and progression through their strain-hardening response under uniaxial tensile loading conditions. Even at the stage of failure, these materials exhibit micron-size cracks which significantly improve the capability to resist against detrimental durability issues. Moreover, these microcracks are constantly reported to be closed through autogenous healing mechanisms with no external interference from outside which significantly improve the mechanical and durability performance and service life of these materials and structures incorporating them. However, the performance of autogenous self-healing in ECC is called into question, especially for late-age specimens since reactions which produce products to plug the micro-size cracks stabilize as the specimens get more and more mature. To clarify this subject, in this study, 1-year-old specimens produced from ECC mixtures incorporated with different mineral admixtures (i.e. Class-F fly ash and ground granulated blast furnace slag) were tested for their self-healing performance. For self-healing evaluation, specimens which were severely preloaded for creating microcracks, were subjected to four different curing conditions which included “Water”, “Air”, “CO2-water” and “CO2-air” for 90 additional days beyond initial 1 year. Tests used for self-healing assessments were electrical impedance (EI) and rapid chloride permeability (RCP). Results indicate that water is a must-have component for enhanced autogenous self-healing efficiency. “CO2-Water” curing results in the most effective self-healing performance regardless of the composition of ECC mixtures. By properly adjusting mixture proportions and curing conditions, microcracks as large as nearly half a millimeter (458 µm) can be healed in only 30 days of further curing. Overall, results clearly suggest that late-age autogenous self-healing capability of ECC can be made as effective as the early-age with proper further environmental conditioning and mixture design.

Due to environmental concerns regarding the use of Portland cement as the principal binder material in concrete and mortar it is imperative to identify alternative materials that could reduce the carbon footprint of the construction industry. One alternative to address these issues is the use of alkali activated materials, in particular, when based on waste streams that currently have no or only limited industrial application. This paper reports a preliminary study into the synthesis of geopolymer mortar utilizing Brown Coal Fly Ash. The ash had a CaO content of ~39%, indicating that synthesis at ambient or low temperature may be feasible. The paper reports initial trials on the effect of curing temperature, ambient to 120 °C, on the mechanical properties of the mortars produced. The results showed that ambient cured mortar achieved a compressive strength of 6.5 MPa at 3 days. A curing temperature of 60 °C gave the optimum results with a compressive strength of almost 20 MPa and a flexural strength of 3.5 MPa obtained.

Calcium-based stabilizing agents have been extensively used to improve the engineering properties of base and subgrade layers of pavement systems. Recently, polymers and chemical stabilizers have become popular due to cost efficiency, ease of application, and fast curing times. This study presents a comprehensive laboratory testing program quantifying the strengths of treated subgrade soils. Here, the strength is defined in terms of California Bearing Ratio (CBR) values. The results of the CBR tests showed that non-traditional stabilizing agents significantly increased the strength characteristics of subgrade soils.

Carbon nanotubes (CNT) modify not only the mechanical but also the electrical properties of the cement matrix, allowing the development of self-sensing cement composites (SSCC). These composites can sense their own deformation through changes in their electrical resistivity, acting as strain sensors, increasing the operational safety of concrete structures by indicating preventive or corrective maintenance. The efficiency of SSCC depends on the electrical properties of the conductive filler and its dispersion degree throughout the matrix. The most commonly employed method of ensuring adequate dispersion of CNT is using chemical dispersing agents. This work aims to compare the effectiveness of two types of plasticizers as dispersing agents for CNT, identifying how they affect the self-sensing capacity of SSCC. CNT contents of 0.10 and 0.20%, by mass of cement, were blended in a cement matrix using two types of commercial superplasticizers as dispersant agents, one naphthalene based and one polycarboxylate ether based. SSCC cement pastes were cast in 50 mm cubic molds with four copper embedded electrodes and cured for 30 days in a humid environment. After curing, an electrical potential was applied through the electrodes and the electrical resistivity of the SSCC was acquired during successive compressive load applications. A 10 V DC power supply was used for this purpose. The changes in electrical resistivity of each cube were correlated with deformations measured by LVDT. Results showed that both the type of superplasticizer used and the CNT content affect the piezoresistive response of SSCC. Naphthalene-based superplasticizer presented better performance as dispersing agent and led to SSCC with better self-sensing response. Results indicated that the chemical basis of the dispersing agent for CNT has great influence on the fabrication of efficient SSCC.

Concrete structures can be subjected to a range of deteriorating processes due to environmental exposure. When subjected to freeze–thaw cycles, the concrete can experience scaling of the surface layer and internal damage that can further lead to cracking and open the path to other deleterious agents. During winter times, the use of de-icing salts is a very common practice to aid in the cleaning and clearance of roads, bridges and tunnels which increases the effects of scaling. Lately, a lot of research has been developed on the use of superabsorbent polymers (SAPs) to increase the durability of concrete structures by means of internal curing, self-sealing and self-healing. The SAP-modified concrete presents a higher resistance to salt-scaling when compared to concrete mixtures without SAPs. In this paper, the scaling resistance of four concrete compositions with and without superabsorbent polymers is studied. One commercial SAP applied to mitigate the autogenous shrinkage and two “in-house” developed SAPs are used. Cylindrical specimens were exposed to 28 freeze–thaw cycles with a 3% NaCl solution. Two of the SAP containing-mixtures showed a reduction of 49% (commercial SAP) and 54% (“in-house” SAP) in salt-scaling in comparison with the reference mixture. On the other hand, another “in-house” developed SAP induced an increase in scaling. The water kinetics of the SAPs was found to play a major role in the performance of the mixtures regarding the scaling resistance.

This paper reports experimental findings on the effect of Bacillus subtilis on crack remediation in thermally degraded Limestone Calcined Clay Cement (LC3) mortars. Mortar prisms measuring 160 mm × 40 mm × 40 mm were cast using LC3 at water/cement (w/c) ratio of 0.5 and cured for 28 days. Half of the 28-day cured mortar prisms were thermally degraded by heating them at 1000 °C in a furnace to induce the cracks while the other half was used as a control. Both cracked and un-cracked mortar prisms were subjected to compressive strength, porosity and accelerated chloride ingress tests. Moreover, half of the cracked and un-cracked mortars were immersed in bacterial solution containing Bacillus subtilis while the other half was separately immersed in curing water until the 90th day. Compressive strength, porosity and chloride ingress tests were also repeated on the 90th day. Microstructural changes in cracked LC3 mortars were carried out using Scanning Electron Microscope (SEM) before and after immersion in bacterial solution. Results showed that at 28 days of curing, un-cracked mortars exhibited higher compressive strength, lower porosity and lower apparent chloride diffusion coefficients than cracked mortars. However, compressive strength, porosity and apparent chloride diffusion coefficients of both cracked and un-cracked mortars were equivalent after 90 days of curing in bacterial solution. SEM images showed visible micro-cracks after thermal treatment and healed cracks with calcite deposition after curing in bacterial solution. In conclusion, Bacillus subtilis was found to improve the crack healing capacity of thermally cracked mortars.

Geopolymer concrete technology is a promising technology for the construction industry. Replacing the conventional resource consuming Portland cement with supplementary cementitious material can reduce the carbondioxide emission as well as energy consumption. It serves as an effective way of disposing industrial wastes that found difficult to be handled in past. Rice husk ash, an agricultural biomass which is rich in silica can be used as an effective source material. In the present study M30 grade GGBS and rice husk ash based geopolymer concrete is developed. Rice husk ash of varying percentage of 5 and 15% is considered to study its effect on mechanical and durability properties. 6 M sodium hydroxide is used. Ratio of sodium hydroxide to sodium silicate used is 1:2. Ambient curing of 28 days is done. The result is compared with OPC concrete specimen to evaluate the performance of geopolymer concrete.

Concrete curing is one of the most critical process to obtain the desired concrete properties. The traditional method of curing is achieved by wetting the exposed surface and preventing concrete from losing moisture. However when the mineral admixtures are applied to concrete, the demand for curing water will be much greater than that in a ordinary Portland cement concrete. If this water is not readily available, it can result in significant autogenous deformation and cracking. In order to overcome these draw back the attention is focused on advanced technology in curing i.e., self-cuing concrete. Self-curing or internal curing is a technique in which no additional water is required to enhance the rate of hydration. These self-curing concretes are also weak in resisting tensile forces, but by incorporating fibers on self-curing concrete both the tensile strength as well as the durability can be increased. In this study, self-curing concrete is achieved by incorporating Polyethylene Glycol (PEG-400) at different dosage (0.5, 1, 1.5 and 2%) by weight of binder content of M40 grade of concrete. To its optimum dosage the hooked end steel fibres are added to this self-curing concrete at different percentage (0.5, 1, 1.5, and 2%) by volume of concrete. The optimum steel fibre content is then determined with respect to strength parameters. The strength properties of self-curing concrete with steel fibers is then compared to that of conventional concrete and self curing concrete.

Construction activities are increasing day by day in different regions, and it requires many natural resources. Alternative materials have been searched for, which can fully or partially replace naturally available material in construction. Stone dust (SD) is one such alternative material which can be successfully used in construction and used as partial replacement of natural sand. The influence of the SD on fresh and hardened properties of concrete are examined and presented in this paper. In this study, sand is replaced by stone dust in different percentages ranging from 0 to 60%. The influence of replacement of sand by SD was analyzed through evaluation of fresh property such as workability (WKA), and mechanical properties, including compressive strength (CS) and splitting tensile strength (TS). Durability properties mainly water absorption (WA), acid resistance (AR) and sulphate resistance (SR) are also determined. The specimen cubes were subjected to 7 Days, 28 Days, and 90 Days and 180 Days moist curing as well as sulphate solution (10,000 ppm) curing. The results show that the optimum replacement level of SD is 40% based on the compressive strength and per cent loss of compressive strength. Sulphate attack is observed minimum at this replacement level. Therefore SD can be effectively utilized in concrete as a valuable alternative for sand and may prove beneficial in construction.

Inclusion of calcite precipitating bacteria during mixing is one of the promising techniques of improving the concrete durability. Concrete cracks can occur due to shrinkage, creep or due to different loading conditions. Bacteria in presence of moisture, precipitates calcite in the microcracks and repair the concrete. Bacillus megaterium was isolated from the soil and introduced in concrete at 105 cells/ml concentration. This paper reports the effect of the inclusion of Bacillus megaterium on the strength, porosity and concrete crack healing under two different curing techniques (standard water curing and air curing). Six different concrete mixtures were made, two control, two with standard bacteria and two with bacteria isolated from the soil for standard water curing and air curing techniques. Bacillus megaterium in concrete resulted in increased strength and decreased porosity of concrete. These results were obtained due to the deposition of bacteria on pores.

The paper investigates the use of lime sludge (LS), fly ash (FA) on unconfined compressive strength, and shrinkage behavior of commercially available kaolinite clay (EPK). The stabilization process was done using lime sludge alone with varying percentages i.e., 2, 4, 6, and 8% by dry weight, as well as a combination with fly ash in varied percentages i.e., 5, 10, 15, and 20% by dry weight. In order to evaluate the strength properties, standard Proctor tests, and unconfined compressive strength (UCS) tests were performed. For estimating the shrinkage, linear shrinkage test was carried out. The UCS samples were prepared based on the optimum moisture content and dry unit weight from standard Proctor tests. The samples were tested after a curing period of 0, 7, and 14 days. In addition, Scanning Electron Microscopy (SEM) tests were performed on UCS samples after shearing. The test results indicated an increase in UCS value with an increase in lime sludge content. Also, the UCS value increased with curing period following a slight decrease. The combination of LS and FA in varied percentages, also had an increase in UCS strength. Also, the UCS value showed an increment in values with the curing period. The reduction in shrinkage behavior of EPK clay was observed with LS and FA. The SEM analysis was conducted to evaluate the reason for strength increase, which was due to the chemical reaction developed between EPK clay, lime sludge, and fly ash.

Construction and demolished (C&D) waste which produced continuously during the construction work can be used for this purpose. The disposal of such material has become a big issue because this kind of deposit covers huge landfill area. In present study, the effect of fines obtained from construction and demolished (C&D) waste and fly ash in the soil mixture was evaluated. Fly ash content as 5, 10 and 15%, C&D waste as 6, 10 and 14% and lime as 2, 4 and 6%. The study results reveal that due to the addition of admixtures, Specific gravity, Maximum dry density (MDD) increases and plasticity index (PI) and optimum moisture content (OMC) decreases. On the other hand specific gravity, PI, MDD decreases and OMC increases with the addition of FA and lime. But the effect of fly ash on unconfined compressive strength value of soil at 7 and 14 days are least as compared to the lime and construction and demolished (C&D) waste. The result of split tensile strength (STS) value of soil after treatment with different admixtures at variable percentage and at different curing periods of 7 and 14 days shows that the maximum gain in strength is due to the addition of 6% lime.

Expansive soils are the problematic soils, this kind of soil is portrayed by its outrageous hardness while drying and with high swelling process on the wetting. This type of soil has been always presented problems for pavements, light loaded structures, by merging under load and by changing volumetrically alongside regular dampness variety. This article illustrates the influence of inclusion of coir in conjunction with Calcium Chloride on expansive soil stabilization is presented. The present study carried out the viability of using the combination of coir and Calcium Chloride in expansive soils. The effect of coir fibre length 10 mm and three percentages (0.3, 0.6, 0.9% by dry weight of soil), coir pith with three percentages (1, 2, 3% by dry weight of soil) and Calcium Chloride with three dosages (0.25, 0.50, 1.0% by dry weight of soil) were considered. Both untreated and chemically treated fibre reinforced with expansive soil samples were prepared. Maximum dry density, optimum moisture content and UCS tests were conducted. Coir consists of pith along with fibre which was separated to study their independent effects of shear strength behaviour. UCS tests were conducted 0, 7, 14 days of curing, it was observed that the combination of 1% coir pith +0.6% coir fiber +1% CaCl exhibited high shear strength. Mix of coir waste and CaCl2 with expansive soil improved the shear strength behaviour of expansive soils. Expansive soil can be successfully stabilized by the coir and Calcium Chloride.

The chapter primarily discusses the time and stage of harvesting, postharvest handling of cardamom, predrying, curing, and artificial drying. Great emphasis is placed on the importance of time and stage of harvesting as these determine the quality of the product. The details of postharvest handling are also discussed in the chapter, such as predrying, curing, sun drying, artificial drying, pipe curing, etc.

The majority of the Australian sealed road network consists of sprayed seal granular pavements. Increasing traffic loadings are placing more pressure on these pavements and there is increasing use of rehabilitation or strengthening treatments that enhance the existing material by the addition of cementitious and bituminous binders. This paper summarises the findings of an Austroads research project aiming to evaluate the deformation performance of foamed bitumen stabilised base materials. The project assessed a crushed rock and a 50% reclaimed asphalt pavement (RAP) blend under accelerated loading using the ARRB accelerated loading facility (ALF). Deformation performance was measured just after construction and sealing to assess the early life properties and after three months of curing. The deformation characteristics were measured with the test pavement heated to around 40 °C at mid-depth to simulate warm weather conditions. The main findings were: (i) The test pavement showed limited pavement surface deformation and low deformation rates under accelerated loading for both the early-life and cured conditions, (ii) when tested at the same temperature, the 50% RAP did not impact significantly on the performance of the pavement, (iii) the foamed bitumen stabilised pavements performed well compared with the asphalt control section. Overall, the research concluded good deformation performance of the foamed bitumen stabilised materials. Subsequent laboratory wheel-tracking tests performed at higher temperatures confirm the resilience of these materials in hot weather conditions.

Two types of mortars were developed for 3D Construction Printing (3DCP), which are normal and lightweight 3D mortars (termed as LATICRETE ® 3D Printing Mortar NW and LATICRETE ® 3D Printing Mortar LW, respectively). This paper presents the properties of the aforementioned mortars in fresh and hardened states, as well as states of curing for cold joint testing. The fresh properties assessed consist of the determination of flow, viscosity, initial set time, and unit weight. In its hardened state, each type of mortar was tested for its mechanical (i.e., compressive and tensile strengths) and freeze-thaw (i.e., ASTM C666) properties. The printability of the mortars was demonstrated by printing small (20-layer; 12 cm high with 6 mm layer thickness; within 5 min) and large-scale structures (a full-scale villa – normal 3D mortar only). Furthermore, a lab-scale test was developed to assess the bonding strength between layers (both cold and fresh joints). The results of the test indicate that the interlayer adhesion at the cold joint can be improved by applying a bonding agent (i.e., LATICRETE® 254 Platinum) on its surface prior to the print.

The waste soil at open dumping area is prone to settlement problems. There are many soil stabilization methods available that can be used to improve soil strength. The addition of egg shell powder and lime for waste soil improvement is studied in this research. Soil stabilization method using the waste material as replacement to improve the strength has been explored widely. In this research, the egg shell powder and lime is added to the waste soil with the mixing portion of 2.5% lime and 2.5% egg shell powder, 5% lime and 5% egg shell powder and 7.5% lime and 7.5% egg shell powder. The compressive strength is conducted on the waste soil samples with different mixing ratio. The optimum value of the compressive strength is simulated using Monte Carlo simulation. In conclusion, there is potential for the waste soil to be improved in terms of strength using lime and egg shell powder. The compressive strength of waste soil is added with 2.5% lime and 2.5% ESP, 5% lime and 5% ESP, 7.5% lime and 7.5% ESP gave the results of 36.39, 70.66 and 337.13 kN/mm2 respectively at curing of 28 days, which satisfies the soil improvement requirement. The Monte Carlo Simulation and optimization of the result using the mean value show that the compressive strength is increase when the data is simulated N = 16 to N = 20. It has proved that the accuracy of the result has increased by using Monte Carlo Simulation and optimization.

Nitrite, salt, seasonings and other ingredients are used for the curing to give unique color, flavor and texture to the meat products. Sodium or potassium nitrite is incorporated into the processed meats to provide desirable meaty flavor, prevent warmed-over flavor, develop a bright reddish pink color and inhibit the microbial growth, particularly for out-growth of Clostridium botulinum spores. Sodium or potassium nitrate can also be used to cure the processed meats. However, nitrate has to be reduced to nitrite by the microorganisms to be effective for curing and mostly used for the slow-cured products including some fermented sausages and country style hams. The safety of nitrite and nitrate used for meat curing was questioned in the 1970s due to their potential to form carcinogenic nitrosamines in the stomach following the ingestion. Conversely, some potential health benefits were also attributed to both nitrite and nitrate in the recent studies since both compounds contribute to nitric oxide production in human body. Nitric oxide produced directly from nitrite has a significant effect on cardiovascular health by controlling blood flow in the cardiac muscle. Thus, the continuing controversy regarding human health concerns from nitrite and nitrate consumption in the diet are evaluated and discussed in this chapter.