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Engineering graduates from Malaysian IHLs have an obligation to practice the knowledge and skills they have gained in a responsible manner to create sustainable living conditions for the society. Ironically though, research indicates that not only are local engineering graduates lacking the competences to do so, local IHLs are also failing to develop the relevant sustainability competences their engineering graduates must develop to be able to function and communicate productively within the sustainability conscious engineering workplace. This issue can be addressed through the advancement of sustainability communication. The present study thus set out to explore this phenomenon further. Using an exemplifying case study approach, perspectives of student stakeholders of a private engineering institution of higher learning's (IHL) were sought, on the inclusion of sustainable development as the context of the professional communication skills module offered within the undergraduate engineering programme at the said IHL. The study employed an action research methodology, through two interventions, i.e. engagement sessions with sustainability practitioners from the industry, and lecturer-peer think-pair-share scaffolding activities. Learner perceptions of the interventions were sought via pre and post surveys, interviews and learner reflections, over three cycles. Finding from the study suggest that the engagement sessions with sustainability practitioners from the industry were more effective. These findings provide important pointers for local IHLs to consider in developing their undergraduate engineering curriculum.

The rate of waste tire generation globally continues to escalate due to increase in vehicle usage. Scrap tires continue to pose serious environmental, health and aesthetic problems. Due limitation in the recycling of scrap tires, one of the most viable solution is to used crumb rubber from scrap tire as partial replacement to fine aggregate in concrete industry. This is rationalized as the production of concrete hit more than 3.8 billion cubic meters annually, therefore, it could provide a solution on conservation of natural aggregate and as well as improve properties of concrete. However, the major setback in the use of crumb rubber in concrete is loss in strength. In this paper, crumb rubber was used to partially replaced fine aggregate at 0%, 10%, 20% and 30% by volume in roller compacted concrete for pavement applications to produce roller compacted rubbercrete (RCR) to improve its flexural strength and ductility. Several trials were done to achieve the combined grading as recommended by ACI 211.3R, and finally a combination of 55% fine aggregate, 40% coarse aggregate and 5% fine sand as mineral filler was used. In order to mitigate the effect of strength loss, silica fume and fly ash were used to replace natural fine sand as mineral fillers. The Results showed that fresh density, compressive, splitting and flexural strengths decreases with increase in partial replacement of fine aggregate with crumb rubber. However using silica fume as a mineral filler was successful in mitigating loss in compressive, tensile and flexural strengths for up to 20% crumb rubber replacement level, while fly ash as a mineral filler mitigated loss in strength for up to 10% crumb rubber compared natural fine sand mineral filler. The flexural strength was found to increase with 10% crumb rubber for all type of mineral filler

The housing sector of Malaysia plays a very prominent role in meeting the major requirements of accommodation throughout the country. However, this sector consumes a handsome amount of resources among which the construction materials are a prime resource. Besides the valuable contribution of housing sector, the building materials used make a significant contribution in embodied CO2 emissions. In order to access the magnitude of CO2 from housing sector, it is necessary that effect of embodied CO2 emissions from the materials used in conventional housing construction in Malaysia shall also be studied. This study focuses on the embodied CO2 emission from the materials used in construction of a typical low cost house which are commonly adopted in Malaysia. The virtual model of selected single storey low cost house was developed using Building Information Modeling (BIM) concept. The results highlighted that bricks (37%), concrete (22%), mild steel (19%), steel rebar (7%) and roof tiles (6%) are the top five materials responsible for CO2 emissions. The overall contribution of single storey house in terms of embodied CO2 emissions is observed to be 34 kg-CO2 / sq. ft. This study has helped to highlight the potential contribution of conventional materials used in typical housing sector of Malaysia.

In the modern building construction, different size of openings are provided in the web of reinforced concrete (RC) deep beams to accommodate utility pipes and ducts of essential services such as electricity cable, telephone network and air-conditioning network. However, accommodation of such openings caused reduction in beam strength, stiffness and caused excessive cracking and deflection. Many investigations were conducted to study the behaviour of openings in beams and relevant strengthening options to reinstate the lost capacity. One of the strengthening options considered lamination of fiber reinforced polymer (FRP) sheets due to its superior properties such as high tensile strength and stiffness, high resistance to corrosion, excellent fatigue performance and good resistance to chemical attack. FRP lamination has been widely accepted by the research community and practicing engineers in the construction industry as the material for strengthening and rehabilitation of common problems. However, quite limited literatures contained the use of FRP to strengthen RC deep beams with openings. This paper discussed the review of eleven different articles contained study of RC deep beams with openings together with effects of strengthening using FRP sheets. The outcome of this review paper outlined the way forward and future research focus in this area.

This paper presents the review of studies performed to investigate the behavior of Reinforced Concrete (RC) beams containing different types of openings. For the last 4 decades, research works involved the investigation of the member strength and development of the design approach for simply supported, continuous and T-beams containing large rectangular openings subjected to torsion, bending and shear forces. The proposed design method suggested the installation of diagonal steel reinforcement bars around the opening for providing the required strength. In recent years, Fiber Reinforced Polymers (FRP) have been widely used as an external bonded reinforcement system for upgrading and retrofitting of concrete structures. FRP as externally bonded reinforcement mainly used to repair and retrofit the damaged reinforced concrete member. However, very limited studies showed the application of the FRP laminates as external reinforcement around openings. Therefore, further investigations regarding the application of FRP laminates to strengthen the large openings in reinforced concrete members are very vital.

To date, various predictive models for high strength concrete (HSC) have been proposed that are capable of generating complete stress-strain curves. These models were validated for HSC prepared with and without silica fume. In this paper, an investigation on these predictive models has been presented by applying them on two different series of HSC. The first series of HSC was prepared by utilizing 100% cement content, while second series was prepared by utilizing 90% cement and 10% Metakaolin. The compressive strength of the concrete was ranged from 71-87 MPa. For each series of HSC, total four cylinders of the size 100×200mm were cast to obtain the stress-strain curves at 28 days.It has been found that the pattern of the stress-strain curve of each cylinder among four cylinders of each series was different from other, in spite of preparing from the similar batch. When predictive models were applied to these cylinders using their test data then it was found that all models more or less deficient to accurately predict the stress-strain behavior.

Study has been conducted to investigate the effect of aspect ratio and volume fraction of PVA fibres on the mechanical properties of concrete. Total eighteen (18) mixes of concrete have been examined using metakaolin up to 5% and PVA fibres of aspect ratio 45, 60, 90 and 120 with volume fraction 1 to 2%. Compressive strength, splitting tensile strength and flexural strength at 7 days and 28 days have been determined to check the effect of volume fraction and the aspect ratio of PVA fibres. It has been found that 2% volume fraction is better than 1% and there is increasing trend up to a certain value of aspect ratio in the strengths of concrete.

In this study, the effect of sugar cane bagasse ash (SCBA) on chloride penetration resistance of concrete was investigated. 100-mm side cubes were cast and cured in water for 28 days followed by six months curing in 4% NaCl solution. The resistance to chloride penetration was assessed by measuring the chloride penetration depth, weight loss, compressive strength loss and bond strength loss. Chloride penetration depth was measured using AgNO3–based method. It was obtained that inclusion of SCBA in concrete significantly reduced the chloride penetration depth, weight loss, compressive strength loss and bond loss that was attributed to the fine particles of SCBA that filled up the pores and prevented the chloride ingress in the concrete.

RC beams as a structural member contain a variety of non-uniform loads. These non-uniform loads caused combined effects of flexure and torsion. There are numerous studies available, that suggests different strengthening schemes using FRP laminates, as a solution for flexure and torsion deficient beams. Most of the experimental studies suggested individual strengthening schemes for flexure or torsional deficiency RC beams. However, the combined effects were not studied due to difference in experimental setup, testing procedure and specimen detailing. Therefore, the outcome of previous studies was needed to combine together to facilitate the strengthening process as a guideline case of such deficiency. Therefore, a combined review is presented by suggesting different configuration for flexure and torsion deficient RC beams. Most of the studies suggested that the application of FRP laminates at the soffit of beam is suitable for flexural strengthening. The application of U-shape or full wrap are suitable for strengthen torsion deficient beams. Similarly, 45° wraps are more effective than 90°wraps for improving ductility of torsion deficient beams.

In the world today, producers of high performance concrete usually look for locally available material to provide low cost concrete. To reduce the total cost of concrete, it is recommended to use a mineral admixture by replacing the cement content while the improvement in the strength of concrete can be achieved by implementing the fibers as a discrete material in the concrete mix. Within this study, a attempt has been given to analyze the properties of self-compacting concrete (SCC) with microwave incinerated rice husk ash (MIRHA) and fly ash as a two types of filler. This was to enhance the properties of SCC with the Stand Chopped Basalt (SCB) fiber having been added to the concrete mix. The experimental work was a fresh and a hardened test with the trend of the result showing the possibility to increase the properties of SCC by using MIRHA and SCB fiber.

Embodied carbon can be defined as the “CO2emissions produced during the extraction of resources, transportation, manufacture, assembly, disassembly and end-of-life disposal of a product”. Calculation of the carbon footprint of buildings is important to promote the construction of low-carbon buildings that release significantly less CO2compared to conventional buildings. However, researchers and practitioners in this area tend to disregard the embodied carbon and pay more attention to the operational carbon when calculating the carbon footprint of buildings. This paper reviews the current state and trend of research on the embodied carbon of buildings with focus on the tools, methods and strategies employed and makes recommendations for future research direction.

In order to improve the mechanical properties of high strength concrete, HSC, several studies have been conducted using fly ash, FA. Researchers have made it possible to achieve 100-150MPa high strength concrete. Despite the popularity of this FAHSC, there is a major shortcoming in that it becomes more brittle, resulting in less than 0.1% tensile strain. The main objective of this work was to evaluate the fresh and hardened properties of FAHSC utilizing chopped basalt fiber stands, CBFS, as an internal strengthening addition material. This was achieved through a series of experimental works using a 20% replacement of cement by FA together with various contents of CBFS. Test results of concrete mixes in the fresh state showed no segregation, homogeneousness during the mixing period and workability ranging from 60 to 110 mm. Early and long terms of compressive strength did not show any improvement by using CBFS; in fact, it decreased. This was partially substituted by the effect of FA. Whereas, the split and flexural strengths of FASHC were significantly improved with increasing the content of CBFS as well as the percentage of the split and flexural tensile strength to the compressive strength. Also, test results showed a progressive increase in the areas under the stress-strain curves of the FAHSC strains after the CBFS addition. Therefore, the brittleness and toughness of the FAHSC were enhanced and the pattern of failure moved from brittle failure to ductile collapse using CBFS. It can be considered that the CBFS is a suitable strengthening material to produce ductile FAHSC.

–The drying shrinkage behaviour of fly-ash-based self-compacting geopolymer concrete (SCGC) was studied for a period of one year. Two SCGC and One OPC-based conventional mixture were used in the present investigation. Drying shrinkage test commenced on the 7th day after casting the test specimens. Once the appropriate curing regime was completed, the specimens from each mix were placed in the laboratory room where the temperature was maintained at 23°C, however, the relative humidity of the room varied between 56 and 64 percent. Strain readings taken at specific intervals were analyzed to determine the time-dependent deformations of each mixture. Test results indicated that the heat-cured fly ash-based SCGC experienced very low drying shrinkage than that of water-cured OPC based concrete. After one year of exposure, in comparison to 466 με, the value experienced by OPC concrete, the drying shrinkage strains of SCGC mix specimens ranged between 141 and 159 με. These values were about 65-70% lower than that of OPC concrete. It is anticipated that the findings of this investigation would help in predicting the behaviour of SCGC. Keywords-Fly ash, Geopolymer concrete, Self-compacting Geopolymer concrete, Drying shrinkage

In this paper, mechanical properties of three series of high performance fiber reinforced concrete (HPFRC) containing 1, 2 and 3% of Polyvinyl Alcohol (PVA) fiber volume are presented. The first series of HPFRC was prepared by using 100% cement, whereas remaining two series were prepared by replacing 10% cement content with silica fume and locally produced metakaolin. All series were designed with water to binder ratio (w/b) of 0.4. The mechanical properties determined in this study include compressive strength, splitting tensile strength and flexural strength. Testing of the specimens was conducted at the 28 days of curing. Experimental results showed that the 3% PVA fiber is the optimum fiber volume to improve the mechanical properties of HPFRC. The variation in the mechanical properties due to the addition of PVA fibers was investigated and presented in the form of mathematical relationship. Further, interrelationship among the mechanical properties was also determined.

Rice is a primary source of food for billions of people and covers 1% of the earth’s surface. On average 20% of the rice paddy is husk, giving an annual total production of 120 million tones. Nowadays, there are two common methods used to dispose the rice husk which is either it is being dump or burnt. Rice husk ash (RHA) which is produced by burning paddy husk led to the issue of ozone layer depletion. It also causes damage to the land and the surrounding area where it is being dumped. Previous studies have pointed out that RHA produced contains more than 80% pure silica and if properly prepared, it is in an active form which behaves very much like cement. Same goes with used engine oil (UEO). Many people are aware that UEO shouldn’t be dumped, but recycled. It is incredibly toxic stuff and a gallon can contaminate one million gallons of water. Pouring it on land doesn’t reduce the risk either as it can seep down into the water table.The objective of this research is to obtain an optimum percentage of inclusion of microwave incinerated rice husk ash (MIRHA) as a cement replacement and UEO in order to produce a better concrete in terms of compressive strength compared to normal OPC concrete. The test results showed MIRHA concrete performed better than normal OPC concrete and the incorporation of UEO and MIRHA in concrete showed the compressive strength give better performance.

Eccentric loads are very common in structures due to building configuration. Unequal slab length, circular ramp, large cantilevers are very common in modern architecture. The RC beams in previous studies were tested under the three and four point uniform loads. Therefore, a simple testing setup was arranged to understand the behaviour of RC beam under eccentric load applied at mid span. In this study the single point load applied eccentrically on RC beam. The beams were tested at different eccentricity and compared with control beam tested under the uniform load or zero eccentricity. Results have shown a drastically reduced crack load up to 54% compared to control beam as the eccentricity increased. However, small changed in ultimate load carrying capacity was observed up to 60mm eccentricity. Eccentric load caused biaxial bending due to high concentration of load on one side of beam, which change failure mode of RC beam from ductile to brittle.

Locally available kaolin has been calcined and used as cement replacing material (CRM) in High-strength concrete (HSC). Total five (05) mixes of concrete have been examined using calcined kaolin (CK) of 0, 5, 10, 15 and 20% by weight of cement. For each mix, compressive strength, splitting tensile strength and flexural strength have been determined by preparing three specimens. The effect of CK on the mechanical properties of HSC has been investigated at age of 7, 28, 56 and 90 days. Multiple linear regressions through least square error have been used to develop the expression and to predict the compressive, splitting tensile strengths and flexural strength of HSC. It has been found that CK as CRM increases the strength significantly. The models may predict the strengths closely match the measurements and optimum replacement of cement by CK.

The construction industry of Malaysia is very dynamic in nature and the adoption of new technological advancements and construction methods has been a prime concerns for its key players and stakeholders. However, the adoption of BIM in such a dynamic industry is observed to be limited and its implementation has not been as successful as it should have been. The study focuses on the identification and prioritization the factors challenging the implementation of BIM in Malaysian construction industry. The data has been administrated through designed questionnaire by identifying the factors / barriers, by literature review, for implementation of BIM in construction industry. The prioritization of such factors is expected to help the major stake holders to address the issues according to their priority which will save lot of previous time and financial with smooth implementation of BIM in Architecture, Engineering and Construction (AEC) industry in future project.

Locally produced metakaolin (MK) as the cement replacing material and PVA fibres has been used. The effect on workability and on the mechanical properties of concrete has been investigated. Total fifteen (15) mixes of concrete have been examined using MK 5 to 10% and PVA fibres of aspect ratio 45, 60, 90 and 120 with 1% volume fraction. Three (03) mixes without PVA fibre have been used as control mixes. For each mix, test for slump, cube compressive strength and splitting tensile strength has been performed. It has been found that MK and PVA fibres causes decrease in slump but use of MK and PVA fibres together improves the workability. The use of MK and PVA fibres has advantageous in increasing compressive strength and splitting tensile strength.

Agricultural and industrial by-products are commonly used in concrete production as cement replacement materials (CRMs) or as admixtures to enhance both fresh and hardened properties of concrete as well as to save the environment from the negative effects caused by their disposal. This paper presents some findings on the effect of Microwave Incinerated Rice Husk Ash (MIRHA) on workability and compressive strength of concrete. It was obtained that the inclusion of MIRHA as partial replacement of cement could significantly improve the compressive strength of hardened concrete while reducing the workability of fresh concrete.

CFRP strengthened reinforced concrete (RC) beams are usually tested under either three points or four point concentric loads; the effect of eccentricity is neglected in many studies. In this experimental program eight RC beams tested in two groups, GROUP ‘A’ & ‘B’. In group ‘A’ four RC beam tested, one control beam tested under concentric load and three under the eccentricity of 40, 60 and 80 mm respectively. The remaining four RC beams in group ’B’ strengthened using carbon fibre reinforced polymer (CFRP) strip and tested under the 60mm eccentricity. The experiment has confirmed the behaviour transformation from flexure failure to local failure due to variation in eccentricity. Therefore, the effects of eccentricity cannot be neglected and required special consideration before applying strengthening scheme on RC beam. The RC beams strengthen using CFRP have the ability to enhanced the load carrying capacity of beams tremendously, but the eccentric load effect on ductility, and failure mode of RC beams.

This research aimed to investigate the suitability of chopped basalt fibers for inducing ductility in High Strength Concrete (HSC). HSC offers a sustainable option to the rapidly growing construction industry particularly in long span bridges, high-rise structures together with other infrastructures. Until near past, efforts were made to achieve much higher compressive strength of HSC, which causes HSC being more brittle. In view of high brittleness of HSC many researchers focused on fiber reinforced concrete to induce ductility. In this study two series of mixes, one with 100% cement and the other with 80% cement with 20% fly ash were studied. In the both of series mixes, fiber content was varied as 0, 0.25, 0.75, 1, 2 and 3%, respectively. Concrete with 0% fibers is known as the control mix. Since, water/binder ratio and super-plasticizer content was kept constant. The tests result indicated that, slump of concrete mixes showed decline with the increment in the fiber content. The addition of chopped basalt fibers did not help to improve the compressive strength of HSC. However, fibers have improved tensile and flexural tensile strength of HSC, also the area under the stress strain curves increased, which are an indication of ductile mode of HSC as well as its toughness. Similarly, tensile to compressive strength and flexural to compressive strength ratio observed a continuous increment with the increase in fiber content as well as the areas under compressive stress- strain curves. In conclusion, chopped basalt fibers have shown their potential for producing ductile HSC.

This study presents the results of an experimental research study on the effectiveness of Sugar Cane Bagasse Ash (SCBA) as a cement replacement material in concrete production. The ordinary Portland cement was replaced with 0, 5, 10, 15, 20, 25 and 30%, respectively bagasse ash, the effect of Sugar cane Bagasse Ash on workability, compressive strength and microstructure of Interfacial Transition Zone (ITZ) of concrete was examined. The results showed that inclusion of Sugar cane Bagasse Ash in concrete up to 20% level significantly enhanced the compressive strength of concrete at all ages; the highest compressive strength was obtained at 5% SCBA replacement level. The ITZ thickness was greatly reduced with increasing the bagasse ash replacement level up to 15%, beyond that the ITZ thickness was slightly increased, however the thickness was still narrower than the normal concrete, it was observed that at 15% bagasse ash replacement level, the interfacial transition zone was homogeneous and there was no gap between the coarse aggregate and the paste matrix.

Reinforced concrete structure is widely used in Malaysia as a common structural system of a building. As a common understanding, reinforced concrete is also known as a composite structure that combined two type of materials which is concrete and steel. Due to rapid development of residential houses, this situation was creating to higher energy consumption by producing high content embodied carbon emission Therefore, three main criteria should be considered in sustainable development that is economic, environment and social in order to produce better environment. This study was developed to produce eco-efficiency design of single story residential house for different optimization of concrete characteristic strength by using economical score and environmental score analysis method. Finding was recorded blast furnace slag reinforced concrete produce an eco-efficiency design than fly ash reinforced concrete due to positive impact to the economical and environmental criteria. Therefore, it can be concluding that waste materials need to be analyzed as an alternative material in concrete because it may produce high content of embodied carbon that give negative impact to the environment.

In the current construction industry, the selection of structural design was important in order to ensure the design were satisfied in term of economic, environment and social as for the purpose to fulfill need of sustainable development. Eco-efficiency has been introduced to be used for the decision-making method in selection of the best design that fulfill requirement of sustainability. This study was develop to integrate analysis of eco-efficiency index for reinforced concrete structural elements by considering economical score and environmental score as a main approach. The classification of the design case for single story and double story house took place from low level to high level of eco-efficiency based on its eco-efficiency index. Result shows single story house was classified from medium low to medium high eco-efficiency design level for all 10 cases while for double story house was classified from low to high eco-efficiency design level.

This paper discussed the effects of modified metakaolin (MK) with nano-silica (NS) on the mechanical properties and durability of concrete. In the first phase, trial mixes of concrete were prepared for achieving the desired value of the 28 days compressive strength, and the charge passed in rapid chloride permeability test (RCPT). In the second phase, statistical analysis was performed on the experimental results using the response surface method (RSM). The RSM was applied for optimizing the mix proportions for the required performance by exploiting the relationship between the mix characteristics and the corresponding test results. A blend of 10% MK + 1% NS as part of cement replacement exhibited the highest mechanical properties and durability characteristics of concrete, concrete mix showed that the 28-days compressive strength (CS) was 103 MPa, which was 15% greater than the CS of the control mix without MK or NS. The same mix showed more than 40% higher flexural and split-tensile strength than the control mix, also it resulted in a reduction of 73% in the rapid chloride permeability value. ANOVA technique was used for optimizing the nano-silica and metakaolin content for achieving maximum compressive strength and minimum RCPT value. Statistical analysis using ANOVA technique showed that the maximum compressive strength and lowest RCPT value could be achieved with a blend of 10% MK and 1.55% NS.

This paper presents the mechanical properties and the microstructure of the high performance fiber reinforced concrete (HPFRC) containing up to 3% volume fraction of chopped Basalt fibers. Three types of the concrete were prepared, out of which, the first type was prepared by utilizing 100% cement content. The other two types of the concrete were prepared by replacing 10% cement content with silica fume and the locally produced metakaolin. Using each concrete type, four mixes were prepared in which Basalt fibers were added in the range of 0–3%; that is, total twelve mixes of the HPFRC concrete were prepared. From each of the twelve concrete mixes, total twelve specimens were cast to determine the mechanical properties of the HPFRC including compressive strength (cube and cylinder), splitting tensile strength, and the flexural strength. In this way, a total of 108 specimens were cast and tested in this study. Test results showed that the addition of the Basalt fibers significantly increased the tensile splitting strength and the flexural strength of the HPFRC, while there was slight improvement in the compressive strength with the addition of Basalt fibers. The microstructure of HPFRC was examined to determine the interfacial transition zone (ITZ) between the aggregates and the paste by using field emission scanning electron microscope (FESEM), which showed the improvement of the ITZ due to the addition of the Basalt fibers.

In order to address maintenance need of specific structures, a criticality analysis of the structures is essential. This paper presents an analysis of experts’ judgment using Analytic Hierarchy Process (AHP). Four criteria; people, assets, environment and reputation were considered as criteria. Sample representatives of Ten (10) civil engineering structures from onshore process plant were treated as alternatives. The judgment of the criteria with respect to the main goal was consistent with consistency value of 0.03. Control building (CB) was considered to be the most critical among the selected structure. Although, the technique is based on subjective experts’ judgment, but is considered very important in designing maintenance plan for existing structures where design data is not available.

Ductile self-compacting concrete (DSCC) also known as ultra-high-performance fiber reinforced concrete with a steel like compressive strength of up to 250 MPa and remarkable increase in durability compared to high-strength concrete can be considered as the most successful recent innovation in concrete construction. The achievement of DSCC has been made possible by the introduction of materials such as superplasticizers, microsilica and steel fibers. Incorporation of steel fibers in the mix made it feasible to design sustainable filigree, lightweight concrete constructions without any additional steel reinforcement. The purpose of this paper is to review the needs of DSCC and the factors influencing the workability of DSCC as well as the effect of the inclusion of steel fibers. Various studies concluded that the inclusion of steel fibers will increase the mechanical and durability properties but reduce the workability.

The aim of this paper is to investigate the serviceability performance of RC beams strengthened through two Ferrocement strengthening techniques as Cast in situ Wire-mesh layers and precast Ferrocement Laminates. To assess the effectiveness of these strengthening techniques, eight (08) RC beams have been intentionally designed and detailed as a tension-controlled section and tested under two-point loading up to service load of 40 kN. Then, beams were strengthened by Cast in situ Wire-mesh layers and by precast Ferrocement Laminates. Experimental results in terms of stiffness have been compared within and across the groups to assess the effect of variation of development length and no. of wire-mesh layers.

This paper presents an experimental study of the influence of different superplasticizer dosage on compressive strength and micro-structure characteristics of interfacial transition zone (ITZ) prepared with fly ash based self-compacting geopolymer concrete (SCGC). The correlations between compressive strength development and microstructure of interfacial transition zone were also investigated. Concrete specimens were prepared with different superplasticizer (SP) dosage namely 3%, 4%, 5%, 6% and, 7% and cured at 70 °C for duration of 48 h. Field emission scanning electron microscope (FESEM) observations revealed that improved performance of concrete was found when the compressive strength increased through formation of dense ITZ between the aggregate and binder matrix at higher SP dosage. There are good correlations between compressive strength and micro-structure characteristics of interfacial transition zone. The FESEM analysis revealed that relatively a loose and porous interfacial zone was found between the binder and aggregate for low SP dosage and theses loose and porous ITZ decreased the performance of concrete by lowering the compressive strength; however, a dense ITZ was found between the aggregate and binder matrix for higher SP dosage that enhanced the concrete performance by increasing the compressive strength.

Fibers addition to concrete and the innovation of self-compacting concrete technology lead to the development of high-performance concrete. However, high intensity fire may adversely affect the performance of this type of concrete. A series of fire resistance test experiments to evaluate the performance of fiber reinforced self-compacting concrete (FR-SCC) slabs consisting of various mix of basalt and PVA fibers were carried out by subjecting the concrete slabs as an element of construction to high intensity Hydrocarbon fire heating condition. The fire testing condition was in accordance with the standard time-temperature fire curve for 120 minutes up to 1100°C heating temperature. The temperatures on the surface and within the concrete slabs were recorded and the performance of each type of FRSCC slabs were evaluated. The performance of Basalt FR-SCC was found to be more resistant to fire in comparison to PVA FRSCC. There residual compressive strength of core samples were tested and SEM analysis were carried out to determine the effect of high intensity fire on the basalt and PVA FR-SCC slabs.

Coal ash is the residue that is produced during coal combustion for instance fly ash, bottom ash or boiler slag which was primarily produced from the combustion of coal. With growth in coal burning power station, huge amount of coal bottom ash (CBA) considered as hazardous material which are normally disposed in an on-site disposal system without any commercialization purpose. Previous researchers have studied the extraction of silica from agricultural wastes such as palm ash and rice husk ash (RHA) and CBA by using leaching treatment method. In this study, the weaker acid, citric acid solution was used to replace the strong acid in leaching treatment process. Result showed that the heavy metal content such as Copper (Cu), Zinc (Zn) and Lead (Pb) can be decrease. Meanwhile the silica can be extracted up to 44% from coal bottom ash using citric acid leaching treatment under the optimum reaction time of 60 minutes with solution temperature of 60°C and concentration of citric acid more than 2%.

Generally the methods were used to characterize soil contamination include collecting samples of soil then analyzing them to recognize contaminates in the laboratory. Commonly, this method of characterizing the contamination of a soil system is the only one agreeable to regulatory societies. However, sample analysis in the lab faces important problems such as soils sampling is really time consuming and costly, sampling is not constant with time and the samples be able to contaminate through sampling and carrying to the lab. Thus several geophysical techniques have been developed which used the dissimilarity in the soil physical properties after soil contamination. Dielectric technique shows high conceivable for characterization diesel contaminated soil. Further use of this technique; rely upon the availability of information about the dielectric properties of the contaminated soil. In this study, the effects of induced by a diesel presence in an unsaturated soil, on the complex dielectric properties were sought. It has been shown experimentally that the diesel presence in an unsaturated soil is traduced by an increase of both dielectric constant and loss factor. A comparison with the existing results in this study and in the literature for saturated soils shows an opposite effect on the complex dielectric properties. The importance of the influence induced by the diesel on the dielectric properties of an unsaturated soil was noticed and compared to a saturated soil. On the basis of the theoretical dielectric mixture models, a justification to these opposite behaviors and their importance has been presented and various models for the two cases have been developed.

The effect of silica fume on the fresh and hardened properties of fly ash-based self-compacting geopolymer concrete (SCGC) was investigated in this paper. The work focused on the concrete mixes with a fixed water-to-geopolymer solid (W/Gs) ratio of 0.33 by mass and a constant total binder content of 400 kg/m3. The mass fractions of silica fume that replaced fly ash in this research were 0wt%, 5wt%, 10wt%, and 15wt%. The workability-related fresh properties of SCGC were assessed through slump flow, V-funnel, and L-box test methods. Hardened concrete tests were limited to compressive, splitting tensile and flexural strengths, all of which were measured at the age of 1, 7, and 28 d after 48-h oven curing. The results indicate that the addition of silica fume as a partial replacement of fly ash results in the loss of workability; nevertheless, the mechanical properties of hardened SCGC are significantly improved by incorporating silica fume, especially up to 10wt%. Applying this percentage of silica fume results in 4.3% reduction in the slump flow; however, it increases the compressive strength by 6.9%, tensile strength by 12.8% and flexural strength by 11.5%.

Since global warming and green buildings have been the concern of the scientific society, efforts were made toward achieving more green and sustainable buildings. One of the efforts was to utilize waste materials such as Coal Bottom Ash (CBA) as cement replacement in the concrete mixture to reduce the harmful effects of cement manufacturing procedure and dumping of coal burning products from utilities industry. This paper studies the effect of replacing cement in concrete mixture by CBA. The porosity of four different concrete mixtures including control mixture was studied using different percentages of CBA, which are 0%, 10%, 20%, and 30% as cement replacement. The results have shown improvement in porosity at 10% and 20% replacement. However, 30% replacement was chosen as the optimum percentage since it showed a 6.825% percentage of porosity which is slightly similar to control mixture, therefore, it utilize larger amount of CBA while providing normal concrete quality, which contribute to the sustainable waste management target of Malaysia.

In this paper, we report the results of the investigations on the effects of sodium hydroxide (NaOH) concentration and different ratio of silicate to hydroxide on the density, rheology and compressive strength of geopolymer cement system used in oil well. Different ratios of Class F fly ash is mixed with different ratios of sodium silicate to sodium hydroxide ratio (2.5, 1, 0.5 and 0.25) to produce different geopolymer slurry densities and dispersant is added to control the rheological properties of the system. The NaOH solution was prepared by diluting NaOH pellets with distilled water according to the specified molarity (8, 10, 12 and 14 M). The solution was then mixed with sodium silicate to form the alkaline solution. Class F fly ash were added to the reactive to form homogeneous mixture, which was tested for its density and rheological properties at surface temperature. The mixture was placed in a 50 mm mould and cured at 930C and 3000 psia for 24 hours and the cubes were tested for destructive compressive strength. The results showed that as the concentration of sodium hydroxide increases, the density of the geopolymer cement increases. There was no significant variation on the density of the geopolymer cement. Also, as the ratio of silicate/hydroxide increases, the viscosity of the slurry increases and the workability of the geopolymer cement become poorer. Furthermore, the compressive strength increases as the NaOH molarity increases however when it reaches 14M, the adverse effect to the strength development was observed.

An investigation of pozzolanic reactivity of ultrafine treated rice husk ash (UFTRHA) was eval-uated using electrical conductivity measurement. This paper is aimed to identify the effect of grinding duration via high speed milling process to the pozzolanic reactivity level. This pozzolanic reactivity assessment was completed by incorporating UFTRHA powder samples prepared at several milling duration in saturated port-landite solution at 40oC. Structure of these mesoporous substances after grinding process were captured using Field Emission Scanning Electron Microscopy (FESEM) accordingly. Based on the findings, experimental re-sults analysis reveal that UFTRHA ground at 15 min has highest pozzolanic reactivity level among all speci-mens. Hence, short period of grinding is sufficient to attain huge amount of specific surface area (SSA) by us-ing high speed milling process. Excessive grinding aid i.e. 60 min produced lower specific surface area hence lower pozzolanic reactivity level. Larger amount of specific surface area leads towards vigorous and higher pozzolanic reactivity.

Waste reduction in the construction sector is essential not just from the position of overall performance, but also interests escalated recently about the detrimental impact of the waste of construction materials on the natural surroundings. The reuse and recycling of construction elements used to be substantial due to material scarcity during the war and post-war era, specifically when the price of virgin materials keep inflating. Nevertheless, the motivation to reuse and recycle construction materials has fallen ever since the flow of raw materials has grown more consistent and satisfactorily. This paper involves an ongoing sequence of waste audits at Universiti Teknologi Petronas (UTP) R&D construction sites. The methodology consists of discussion, observation and quantitative evaluations of the kinds and distribution of wastes. The finding of this study demonstrates that the project aimed at both minimizing the volume of waste generated and diverting as much waste as possible from landfill that contribute to the recycle with over 1200 tonnes of material which constitute about 73% of recycle and reused rate mainly from timber and metal.

Fiber-reinforced concrete (FRC) is a well-recognized construction material because of its vast application in civil engineering structures. The use of steel fibers in FRC is well established in terms of reliable modeling of its mechanical characteristics; however, new fiber reinforcements also need attention. This paper analyzes the compressive stress-strain behavior of three mix types of high-strength fiber-reinforced concrete (HSFRC) having compressive strengths of 70–85 MPa and containing 1–3% volume fractions of basalt fibers. In the first mix of HSFRC, 100% cement content was utilized whereas 10% cement content was replaced by silica fume and metakaolin as replacement materials in the remaining two mixes. Based on the experimental data, an analytical model to predict the complete stress-strain behavior of HSFRC is proposed that shows good agreement with experimental results.

As the development and application of fiber reinforced polymer (FRP) composite materials to different engineering structures are increasing, composite patching techniques are being considered as alternatives to traditional methods of repair to Jacket-type steel structures. The present paper describes a developed finite element model (FEM) of corroded tubular steel member, representative of offshore steel jacket member, and a FEM of wet lay-up CFRP patch repaired corroded tubular steel member using ANSYS software and ANSYS Composite PrepPost (ACP), which is an add-on module to ANSYS software. The numerical study results reveal that the three-ply composite patch reduces the maximum von-Mises stress, maximum stress intensity and maximum shear stress of the corroded tubular steel member by approximately 20.6%, 18.2% and 18.2%, respectively. Moreover, ply-wise stress and strain results indicate that maximum tensile stress and strain was observed in the first ply and maximum compressive stress and strain was noticed in the third ply. Failure analysis demonstrated that under first applied load and moment there is no critical region or critical failure criteria in composite patch, but under increased axial load of 1300 KN, composite patch fails.

The development of fly ash and microwave incinerated rice husk ash (MIRHA) blend as the source material for geopolymer concrete was studied through the observation of the hardened specimen strength. Compressive and bonding strength of the specimen indicate the significance of curing temperature in the activation of MIRHA particles. The elevated temperature is presenting a suitable condition for rapid dissolution of silicate monomer and oligomer from MIRHA surfaces, which supports the formation of supersaturated aluminosilicate solution in geopolymer system. It contributes to the refinement of pores structure via the increasing geopolymer gel growth, as observed in the consistent compressive strength development of ambient-cured specimen to the oven-cured specimen. Densification of geopolymer framework appears to be the main contributor to the increasing bonding capacity of geopolymer binder. 2012 Elsevier Ltd. All rights reserved.

In this paper; results of the degree of hydration of the pastes and the compressive strength of the 50 mm cubes prepared with the 100% cement and fly ash blended cement were determined. 24 hours after casting mortar cubes and the paste samples were cured for 28 days in the fog room. After 28 days curing, a set of three cubes and a paste sample was dried in the 100%, 75%, 65%, 40% and 12% ambient relative humidity at the constant temperature of 27°C. Drying conditions showed significant effects on the compressive strength and the degree of hydration. Highest compressive strength of 70 MPa was measured of mortar cubes dried in 100% RH; similarly, 97% degree of hydration was obtained for 100% cement samples dried in the 100% RH. For mortar cubes dried in 12% RH, the compressive strength was measured between 47 and 53 MPa. The similar paste samples showed the maximum degree of hydration as 81%. Statistically valid correlations were obtained between the degree of hydration and the compressive strength of normal and blended cement system.

High amount of reactive silica is ubiquitous in pozzolanic reaction for concrete strength increment. Rice husk ash (RHA) is proven contains high content of amorphous silica that is essential in the pozzolanic reaction of effective additive in concrete. Nevertheless, incorporation of RHA as cement replacement material (CRM) or additive is very minimal in current concrete industry. Therefore, improvement on the RHA properties by introduction of thermal and chemical pretreatment prior to incineration process is considered as a promising way in order to achieve the goal. This treatment process has been reported widely in literature. In this paper, the effect of treated rice husk ash (TRHA) and non-treated rice husk ash (NTRHA) incorporated mortar in terms of its compressive strength and microstructure properties are examine subsequently. The strength activity of TRHA from the optimum treatment process was measured by testing the compressive strength of mortars. The highest compression value obtained was 50.73MPa with 3% UFTRHA replacement at 28 days. At a longer curing period i.e. 90 days, it was recorded that 3% of UFTRHA mortar had the highest compression value at 53.87MPa. As for microstructure properties, a denser microstructure with excellent aggregate bonding and cement matrix in the interfacial transition zone (ITZ) was observed.

Pozzolanic reactive material is considered as one of the most essential characteristic of cementing additive material in concrete technology application. Normally, the reactive material contains abundant silica that enhances concrete strength activity. Undeniably, it is proven that rice husk ash (RHA) possesses large quantity of silica that induces the pozzolanic reaction in concrete. Nevertheless, usage of conventional RHA is still widely accepted in concrete industry nowadays. One of the setback of conventional RHA incorporation is simply because of its properties inconsistency. Therefore, enhancement on the RHA properties by introduction of a specific pretreatment prior to incineration process is expected to provide an alternative way in order to produce highly reactive cementing additive material from locally available agricultural by-product, the rice husk. In this paper, a total number of 30 experimental set points was conducted. Statistical analysis was conducted for four independent variables and two responses using Response Surface Method (RSM). The analysis was completed using a commercial software set (Design-Expert) for experimental design and analysis. The independent variables were HCl concentration, soaking time, burning temperature and soaking temperature. Meanwhile, the responses investigated in this study were including cumulative pozzolan percentage and electric conductivity decrement from 0 to 2 minutes. As for the statistical analysis of the data for response 1, the cumulative pozzolan percentage calculated from the model was in-line with the experimental data, with R-squared value of 0.9565. Hence, the result validates the precision of the model. On the other hand, the R-squared value for response 2 which is the EC decrement from 0 - 2 Minutes, it shows that the model was in agreement to the experimental values at 0.9342. Thus, it is again justifies the model accuracy.