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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.

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.

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.

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.

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.

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.