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In this study, a method for determining the setting time and the porosity of fly ash-based geopolymer binders (FAGPBs) has been established. This method permits a real-time monitoring of the geopolymerisation and hardening progressions. A parallel plate capacitor cell technique was used to determine the dielectric constant e r ' and dielectric loss factor e r ' ' of fresh and hardened mixes. Equivalent model-circuits of the measurement system were developed, and the accuracy of the system was verified. The dielectric properties were monitored at different ages until 56 days over a frequency range of 0.1–60 MHz. The alkaline solution to fly ash ratio, sodium silicate to alkaline solution ratio, and sodium hydroxide solution molarity were varied to study their effects on the dielectric properties. It was found that dielectric properties can provide valuable information when measured in the frequency range of 10–25 MHz. In this range, the dielectric values responded well to the variations with age and with mix properties. The relationships between the dielectric properties and the different physical states and constituent materials of FAGPBs could be used for quality control applications. The e r ' and e r ' ' time plots were effectively utilized to determine the setting time and the rate of geopolymerisation of FAGPBs. Measurements showed a strong correlation between e r ' and porosity; the e r ' values decreased 2.3-fold over a porosity range of 3–15%. The proposed regression models can be further used in determining the porosity of FAGPBs at a high accuracy level.

Rubbercrete is made of partially replacing fine aggregate, in normal concrete, with crumb rubber (CR) from scrap tires. Despite several advantages of rubbercrete, one of the most hindering factors on using it in the construction industry is the absence of specific mix design to optimize the mix ingredients. Response surface methodology (RSM) optimization has been incorporated using the design expert to eliminate the difficulty in obtaining the anticipated results. Experimental data of 45 rubbercrete mixtures (from the previous study) have been utilized to develop ANOVA models. These models have also been validated to predict the properties of rubbercrete based on different percentages of CR content and w/c. All models are significant with Prob > F is less than 0.05, and the difference between predicted R-squared and adjustable R-squared is less than 0.2. Also, an experimental validation has been performed for three of the optimized mixtures, and the results have been compared, and the variation in the results have found to be less than 5%. It has been concluded that the optimization can be performed for any target strength with desirability as approximately one by improving the performance, reliability for the product and processes.

There is a global outcry over the speedy deterioration of structures in oil and gas facilities. While marine environment is considered the leading factor in the deterioration of offshore structures, there is no single factor considered as the main cause of the problem in onshore structures. Therefore, the aim of this paper is to present the result of global survey on the major factors causing the deterioration of concrete structures in onshore oil and gas facilities. To realize the objectives of the paper, an e-questionnaire was administered through two International LinkedIn groups with a membership mainly dominated by experts in onshore oil and gas facilities. 159 respondents completed the questionnaires, and the reliability of the responses was calculated to be 0.950 which is considered excellent. Relative importance index was used in ranking the factors, and it was observed that environmental factors ranked as the dominant factors causing the deterioration of concrete structures in onshore process plants. Another important finding in the study is the role that experience plays on the perception of experts on the causes of defects on concrete structures.

Almost all life cycle assessment methods of carbon footprint for conventional housing in tropical region have either ignored the impacts of recurrent carbon or considered based on random assumptions. To ensure the green and sustainable urban built environment, particularly in tropical regions, an accurate monitoring and control of carbon footprint requires a comprehensive assessment of all phases of project life cycle, including maintenance. This article presents an innovative and dynamic approach of forecasting of carbon footprint including the recurrent carbon by combining a statistical (simple and multiple regression) and simulation (3D parametric prototyping) technique in a partial LCA (cradle to site) study for a tropical built environment. The developed multivariable regression model satisfied the statistical criteria of an efficient and consistent tool as the average percentage error of the predicted and observed values was found within the acceptable range. The average contribution of CO2 ranged from 2.0 tons to 40 tons for 25 to 100 year of service life span. Ceramic tiles, false ceiling, plaster and roof tiles remained the top materials. The model validation observed an acceptable average error range from (−) 3.24% to (+) 8%. The study analyzed the factual recurrent carbon footprint impacts and justified the importance of its inclusion in preemptive mitigation toward sustainability concerns at very early stage of the housing project. © 2017 American Institute of Chemical Engineers Environ Prog, 2017

An engineered cementitious composite (ECC) is a type of high-performance fibre-reinforced composite developed based on micromechanical principles. To improve the modulus of elasticity and minimise the drying shrinkage in self-compacting (SC) ECC without adversely affecting its ductility, nano-silica (NS) is included in the cementitious composite. Twenty SC-ECC mixtures were proportioned, cast, cured, and tested to determine the fresh and hardened properties by using two variables: polyvinyl alcohol (PVA) fiber and NS particles. Five levels of NS (0%, 1%, 2%, 3%, and 4%) and four levels of PVA (0.5%, 1%, 1.5%, and 2%) were considered. A response surface methodology was used to conduct multi-objective optimisation and develop mix proportions that produce the best response to the compressive strength, modulus of elasticity, and energy absorption. It was found that mixtures with 2% PVA and 1.89% NS produce the most desirable responses.

Geopolymer system is new binding materials in concrete industry that is produced by the alkaline solution and materials rich in aluminosilicate such as fly ash. The effect of the alkaline solution to fly ash ratios of 0.3, 0.4 and 0.5 on mortar geopolymer properties was an issue in this study. The results showed that the higher alkaline solution to fly ash ratio improves the workability and brings a longer setting time, whereas the lower alkaline solution to fly ash ratio gains the significant compressive strength. It was a similar pattern with conventional mortar used ordinary Portland cement, which the compressive strength at 7 days was 85%-90% for 28 days compressive strength, whereas conventional mortar is only 65%-75%. This was due to the higher reactivity in geopolymer system that was faster than the pozzolanic reaction.

In the production of sustainable concrete, it is quite essential to develop highly reactive silica rich materials to substitute cement. Sugarcane bagasse ash as one of the agricultural based pozzolan gained less popularity due to its relatively low amorphous silica content after incineration process (

In this research, performance of limestone and oil palm shell (OPS) as the alternative aggregates in fly ash based geopolymer concrete was evaluated based on the fresh and hardened concrete test. Fly ash and oil palm shell were studied due to their abundant availability as industrial and agricultural waste. Experimental works were conducted by replacing the portion of coarse and fine aggregate in concrete with limestone and oil palm shell in various percentages. Evaluation of its performance was done based on slump, compressive strength, and porosity test. Microstructure analysis was added via Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray (EDX) test to support the generated hypothesis. From the fresh properties test, the increasing amount of limestone and OPS have shortened the setting time of fresh geopolymer concrete, even though they presented small variations in the slump's height and diameter results. The availability of Calcium Aluminate Silicate Hydrate (C–A–S–H) structure in limestone based specimen and higher polycondensation rate due to optimum water content in OPS based specimens have stimulated the rapid production of geopolymer gel and improved the strength performance of geopolymer concrete in ambient curing condition. Moderate water absorption from OPS fibers and additional dissolution of Al and Si elements due to formation of C–A–S–H gels from limestone inclusion have presented 10% OPS and 25% limestone as the optimum replacement to river sand and coarse granite aggregate, respectively. In ambient curing, 25% limestone presented a 35.23% higher strength while 10% OPS had 11.01% higher strength than control. An escalation to the curing temperature reduced the efficiency of both aggregates, where only 25% limestone was able to produce specimen with 2.34% higher strength than control A supportive analysis from SEM and EDX has also revealed the existence of poly(sialate), poly(sialate-siloxo), poly(sialate-disiloxo) and sialate link in the geopolymer matrix. From this research, the applications of limestone and oil palm shell in geopolymer concrete have presented a nurturing result, particularly as the alternative aggregates in ambient-cured application.

Geopolymers are novel binding materials produced by the alkaline activation of rich aluminosilicate materials. Geopolymer binders are considered as green building materials that have increasing potential to replace the ordinary Portland cement in the concrete industry. This study investigated the alkali solution effects on the physical and mechanical properties of the high calcium fly ash based geopolymers. The parameters involved in this study were the NaOH solution molarity and the Na 2 SiO 3 /NaOH ratio. Three NaOH concentrations (8, 10, and 12 molars) were investigated. The Na 2 SiO 3 /NaOH ratio was varied between 1 and 2.5. The results showed that the studied parameters significantly affected the properties of the produced geopolymer mortars. The workability and setting time were found to decrease by increasing the NaOH concentration or by increasing the Na 2 SiO 3 /NaOH ratio. The influence of the NaOH concentration was higher on the workability and setting time while the Na 2 SiO 3 /NaOH ratio highly affected the compressive strength. The initial setting time was in the range of 45-105 minutes while the final setting occurred quickly after that within 70-115 minutes. Oven curing method resulted in high strength at early ages where all of the mixes were able to achieve more than 75% of the 28 days strength within the first 3 days. The 28-days compressive strength ranged between 60-85 MPa, which promotes the use of the high calcium fly ash for the production of early high strength geopolymer concrete.

Recently, incorporation of cement replacement material (CRM) in concrete has gained considerable attention throughout the world. It is known that the commonly used CRM in current concrete industry is silica fume (SF), pulverized fuel ash (PFA) and rice husk ash (RHA). RHA is an agricultural waste from rice milling process. Rice farming activities is one of the main crops planted in Malaysia and therefore, the rice husk abundantly generated every year. RHA exhibits positive pozzolanic reaction during concrete strength development. The material contains amorphous silica and hence it contributed towards enhancement of various concrete properties. This paper presents a short review of RHA properties as CRM and pozzolanic reaction determination.

This experimental investigation has been carried out to examine the effects of temperature and duration on Malaysian kaolin to form highly reactive metakaolin. Metakaolin has been produced through the calcination process at temperatures 600–800 °C (1112–1472 °F) for the duration from 1 to 5 h. X-ray diffraction and loss on ignition are the usual process to identify the optimum temperature and duration of calcination required. In this study, to confirm the reactivity of metakaolin, compressive strength, splitting tensile and flexural strength of concrete at the age of 7, 28, 56 and 90 days have been investigated using locally produced metakaolin as cement replacing material. It was found that locally produced metakaolin enhance the mechanical properties of concrete and compressive strength is about 5% higher than silica fume concrete at the age of 28 days. This study divulges that calcination at 800 °C (1472 °F) for 3 h is the most suitable condition to convert kaolin into highly reactive metakaolin.

Steel slag waste is a by-product of steel mining industry. Effort to utilize the steel slag in concrete production has been failed due to its high contents of MgO which causes volumetric instability of the hardened concrete. Researchers also have failed to utilize the steel slag in the sub-base of road construction due to its low compaction ratio. Geopolymer concrete is a new sustainable material made of mainly two materials which are alkali liquid and source material. The source material usually has to be pozzolanic. However, the chemical composition of the steel slag has shown that the steel slag is not considered as a pozzolanic in accordance to the requirement of the ASTM. Therefore, a special modification has been carried on and a geopolymer steel slag brick has been developed. The new developed geopolymer steel slag brick has compressive strength of about 10 MPa which is made the brick suitable for construction of a load bearing walls.

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.

Alkali Silica Reaction (ASR) is a physiochemical reaction which affects the strength and durability of concrete. ASR occurs due to a chemical reaction between alkali oxides presents in the cement paste and reactive silica in aggregate. This reaction could lead to the volume expansion, cracking, loss of strength and potential failure of the concrete. This research aimed to investigate the potential alkali silica reactivity on geopolymer concrete. Specimens were prepared using Class F fly ash as binder while sodium hydroxide and sodium silicate as alkaline activators. ASTM C1260 was adopted to determine potential alkali silica reactivity by measuring the length change of mortar bar as well as the decrease in compressive strength test. Results show that fly ash based geopolymer concrete is less vulnerable to ASR as the expansion of mortar bar is below the threshold of ASTM standard limit which is 0.10% of expansion. This test ensures that the durability of geopolymer concrete is excellent and can withstand a long life span.

Geopolymer is associated with the alkali activation of materials rich in Si and Al, and alkali activator such as sodium hydroxide is used for the dissolution of raw material with the addition of sodium silicate solution to increase the dissolution process. However, the trend of strength development of geopolymer using sodium hydroxide alone is not well established. This paper presents an evaluation on compressive strength of fly ash–based geopolymer by varying curing time with respect to different curing temperature using sodium hydroxide as the only activator. The samples were cured at room temperature and at an elevated temperature (60°C). Further analysis on the microstructure of geopolymer products cured at 60°C was carried out using Field Emission Scanning Microscopy (FESEM). It can be observed that the compressive strength increased as the curing time increased when cured at room temperature; whereas at elevated temperature, the strength increased up to a maximum 65.28 MPa at 14 days but gradually decreased at longer curing time. Better compressive strength can be obtained when the geopolymer was cured at an elevated temperature compared to curing at room temperature.

Geopolymer is produced from the alkali activation of materials rich in Si and Al such as fly ash. Sodium hydroxide (NaOH) with high concentration is normally used in geopolymerization. Limited research has been done with low concentration of alkali activator. This study confirms that KOH with low concentration affect the setting time and compressive strength of geopolymer in order to have good mechanical properties. Optimum result was observed at 4.5 M KOH. This result can be further developed to produce geopolymer with low alkaline activator for coating applications.

The current work presents the effect of alkali concentration on fly ash based geopolymer material. In this work geopolymer material was prepared with a fixed Si/Al ratio (1.85: 1) and varied solid to water ratio and NaOH concentration. All samples were tested to establish the role of alkali on the strength. Samples prepared with 8M of NaOH showed the highest compressive strength. In this regards, Fourier transform infrared spectroscopy (FTIR) results support this observation where broad band becomes sharper and shifts towards lower wavenumbers. In XRD the broad hump slightly shifted towards higher values which indicate the formation of new product. These findings show that to obtain required processing time at desired mechanical strength for a specific application of geopolymer, the suitable concentration of alkali must be established.

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.

The present study has been performed to see the effect of varying Si/Al ratio (1.85 to 3) by using same concentration of NaOH and same solid/water ratio for the development of mechanical properties at 28 days of room temperature and also select the Si/Al ratio for coating application. The performance of the geopolymer was investigated on the basis of compressive strengthSEM along with EDS. Pure sodium hydroxide specimens displayed decreased strength. However the combination of sodium hydroxide and sodium silicate specimen with aSi/Al ratio of 2 showed maximum strength, whereas the specimen after Si/Al ratio 2 showed decrease in strength.

Concrete has been used in the construction industry since long times. It is probably the most widely used construction material in the world, largely due to the abundance of the raw materials for cement manufacture, low relative cost and the versatility and adaptability of concrete in forming various structural shapes. Massive production of concrete and the associated substantial manufacture of cement have however been observed to have a very negative impact. One of the biggest issues of growing concern at the moment faced by concrete industries is the impact of cement production on the environment. The production of cement not only depletes significant amount of natural resources, but also liberates a considerable amount of carbon dioxide (CO2) and other greenhouse gases into the atmosphere as a result of decarbonation of limestone and the combustion of fossil fuels. In addition, cement is among the most energy intensive construction materials, after aluminium and steel [1].

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.

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.

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.

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.

Interest on building insulation has started to develop among the research community in recent years. Kapok fibres have the potential to become a roof insulation material because of its low thermal conductivity. This paper reviews studies on kapok fibre as insulation material. It is revealed that there were no reported findings on the application of kapok fibre as roof insulation.Thorough study is highly recommended in this area since kapok fibre has good thermal and acoustic properties.

Soil contamination with petroleum hydrocarbons has become one of the most serious problems due to its negative repercussion on ecosystems. For this reason, different analytical techniques have been developed to evaluate the quantity and the quality of organic pollutants using electrochemical techniques, and a geophysical methods have been developed which utilizes the contrast caused by the contaminant on physical properties of the soil dielectric methods shows high potential for characterization kerosene contaminated soil and determination of the level of contaminant. The potential of dielectric measuring techniques for soil characterization has not been fully explored. For this purpose, dielectric measurements, in the frequency range from 100 kHz to1000 kHz, were carried out in sandy soil samples, contaminated with solutions of kerosene, at different concentrations. The differences of the dielectric behavior with contaminant content suggest that the monitoring of complex dielectric constant has the potential to quantify contaminants.

Ductile self-compacting concrete (DSCC) is one of the advanced materials which combines self-compacting abilities and ductility to address the current industry problems. As the fly ash and microwave incinerated rice husk ash (MIRHA) are beneficial to the properties of concrete, it has led to a research on the effects of ternary blends of MIRHA, fly ash and cement in DSCC. Up to 20% of cement in DSCC was replaced with MIRHA and fly ash with 10% by weight respectively whilst maintaining satisfactory self-compacting abilities. The effects of MIRHA and fly ash on mechanical strength and chloride penetration depth of DSCC were determined. The control DSCC mix was compared with the DSCC mix with MIRHA and fly ash. The results shown that substitution of MIRHA and fly ash into DSCC gave positive effects, it improved the mechanical properties and chloride permeability.

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 benefits of Microwave Incinerated Rice Husk Ash (MIRHA) as partial cement replacement materials in DSCC mixes has led to the research on the possibilities of combining both MIRHA and fly ash as an addition in DSCC replacing up to 20% of cement volume whilst maintaining satisfactory properties. The addition of both materials can improve concrete properties and reduce the cost of DSCC production. These supplementary cementitious materials are expected to give positive effects on the concrete abrasion and impact resistance. The incorporations of both MIRHA and fly ash in DSCC as cement replacement materials are considered as a new type of concrete. Therefore, it is important to have a complete knowledge on the behaviour of the composite material when being subjected to repetitive dynamic loading. The test results showed that MIRHA and fly ash combination in DSCC improved both abrasion and impact resistance of DSCC compared to reference specimens.

The aim of the research is to develop engineered cementitious composite mixtures satisfying the self-compacting concrete requirements and to evaluate the hardened properties of self-compacted ECC mixtures. To enhance the concrete performance, PVA is used. The PVA improved some characteristics and properties of the concrete. Ten mixes with different Polyvinyl Alcohol (PVA) fiber contents (0.0%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5% and 5.0%) have been prepared. Three cubes (100mm x 100mm x 100mm), three beams (100mm x 100mm x 500mm) and three cylinders (150mm diameter and 300mm height) have been cast for each mix and tested at the age of 7 and 28 days for compressive strength and at age of 28 days for splitting and flexural strength. The V-funnel, L-box and slump test also have been conducted to access the fresh properties like workability and flowability of the concrete. The results indicated the increase in the strength of the concrete and the formulas for predicting the compressive, splitting and flexural strength from PVA (%) has been developed.

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.

Alkali Silica Reaction (ASR) is a chemical reaction which affects both strength and durability of concrete. ASR occurs due to a chemical reaction between alkali oxides presents in the cement paste and reactive silica in aggregate. This reaction could lead to the volume expansion, cracking, loss of strength and potential failure of the concrete. This research aimed to investigate the potential alkali silica reactivity on geopolymer concrete. Specimens were prepared using Class F fly ash as binder while sodium hydroxide and sodium silicate as alkaline activators. ASTM C1260 was adopted to determine potential alkali silica reactivity by measuring the length change of mortar bar as well as the decrease in compressive strength test. Results show that fly ash based geopolymer concrete is less vulnerable to ASR as the expansion of mortar bar is below the threshold of ASTM standard limit which is 0.10% of expansion. In term of strength, the geopolymer concrete did not reduced instead it increased. From the results, it has indicated that both tests ensure that the durability of geopolymer concrete is excellent and can withstand a long life span.

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.

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.

Ductile self compacting concrete (DSCC) is one of the advanced materials which combines self compacting abilities and ductility to address the current industry problems. A study on DSCC with various cement replacement materials was conducted. Up to 20% of cement in DSCC was replaced by Microwave Incinerated Rice Husk Ash (MIRHA), silica fume (SF) and fly ash (FA) in certain ratios. The experiments of self compacting ability such as V-funnel test, slump flow and L-box test were conducted in order to ensure the DSCC with various cement replacement materials fulfilled the requirements for self compacting. Besides that, comparison of compressive strength is made between the control DSCC and DSCC with various cement replacement materials. The results show that DSCC with replacement of 10% FA and 10% MIRHA achieved the highest compressive strength without scarifying the self compacting abilities.

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.

The benefits of microwave incinerated rice husk ash (MIRHA) as partial cement supplementary in concrete mixes has led to the research on the possibilities of combining both MIRHA and fly ash in DSCC replacing up to 20% of cement volume whilst maintaining satisfactory properties. While concrete strength increases, explosive spalling may occur in the event of fire. It is important to have a complete knowledge on the behaviour of the composite material subjected to high temperature. In this study the specimens were water-cured for 28 days before subjected to fire flame temperatures of 200, 400, 600, 800, 1000 and 1200 °C for exposure duration of 1 h. After burning, concrete specimens were allowed to cool down in two ways, gradually and immediate cooling. Visual inspection, mass measurement and residual compressive strength of the concrete were made and the results were compared with reference specimens. The test results showed that the weight and compressive strength decreased when the fire flame temperatures were increased and the additions improved the spalling effects on the concrete when subjected to high temperature.

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.