Key Engineering Materials Vols. 594-595

Abstract: In relation to the conventional concrete then foamed concrete (FC) is weaker. Therefore FC was added by Rice Husk Ash (RHA) to alter the strength without eliminating its characteristic as aerated concrete. Actually function of RHA is substitute the sand partly. The strength of concrete affects to prevent the dynamic impact loading. However FC as aerated concrete can absorb energy impact by its porosity. Both of characteristics were presented in this investigation. SEM and EDS detected that pozzolanic reaction was done when FC was processing hydration of cement in admixture. The presence of RHA increased the strength of concrete owing to cement hydration process and pozzolanic reactivity of RHA. The result of impact loading on slab FC target displayed that FC with RHA was more shallow than without RHA. Beside of that local damage showed that FC with RHA denser and is not impression of fragments than FC without RHA.

Abstract: Geopolymer is an inorganic polymer performed in synthesis process of an aluminosilicate material which activated by alkaline activator solution. Marine clay, considered to be a waste substance which have an important aluminosilicate sources in developing geopolymer synthesis since it contains sufficient amounts of alumina and silica. In this experimental study, local marine clay composition was been identified to determine the amount of alumina and silica. The raw sample compositions were identified by using X-ray fluorescence (XRF). Incorporated with it composition, compressive strength of brick were been tested in aged of 1, 2 and 3 day and compared with local production of cement brick (CB). This research is aimed at determining the properties of Kuala Perlis marine clay in order to verify its suitability as a pozzolana materials as well as the sufficient amount of Al and Si to enhance the properties of geopolymer brick.

Abstract: With increased activity in construction, deficiency of building materials and construction waste improvements have encouraged the development of new building materials. Conventional construction bricks are usually made from clay and sand, which are mixed and molded in various method and need to be dried and burned. Geopolymer bricks making process consume less energy and low cost in term of production compared to conventional bricks. The development of geopolymer brick is an important step towards produce bricks with better performance and environmental friendly material This research focusing on the processing process of the clay-based geopolymer brick from the mixing until the curing by using a geopolymer brick making machine.

Abstract: Drying shrinkage, compressive strength and microstructural analysis of metakaolin based geopolymers partial replacement with Parawood ash was investigated. It was involved different SiO₂/Al₂O₃ and CaO/SiO₂ ratios. Characterization of geopolymer mortar was determined on drying shrinkage, compressive strength, mineral phases and microstructure was analysed by X-ray diffraction and scanning electron microscopy techniques. Test result of highest compressive strength was about 71 MPa at 6-h (4-h in oven at 80oC and 2-h ambient temperature). Voids-cement ratio is the most effect on the unconfined compressive strength of this metakaolin geopolymer mortar.

Abstract: The compressive and flexural performance of flax fibre reinforced polymer (FFRP) confined coconut fibre reinforced concrete (CFRC) structures were investigated. The mass content of coconut fibre considered was 1% of cement. Eighteen cylinders were tested under uniaxial compression and 12 beams were tested under four-point bending. Test results show that in compression, both FFRP tube and FFRP wrapping confinements enhance the axial compressive strength and ultimate strain of concrete significantly, e.g. the ultimate strength of 4-layer FFRP tube confined CFRC is 94% larger than that of the unconfined CFRC. In flexure, the FFRP tube increases the lateral load bearing capacity and the deflection several times larger than the unconfined concrete columns, e.g. the ultimate lateral load of 4-layer FFRP confined PC and CFRC are 1066% and 946% larger than the corresponding unconfined PC and CFRC specimens. In flexure, coir inclusion can affect the failure mode of the FFRP-CFRC composite structure significantly.

Abstract: This research paper describes the investigation of new innovative form of lightweight composite known as Profiled Steel Sheeting Dry Board (PSSDB) wall panel system. Profiled Steel Sheeting Dry Board (PSSDB) is categorized as Industrialized Building System where paneling system has been developed to substitute the traditional structure of brick wall. The proposed system is a novel form of double and single sheathed composite panel. It consists of dry board and profiled steel sheet for middle core, attached by screws at both surfaces forming the composite action. This paper present the experimental results of twelve full scaled samples of PSSDB wall panel by using Cliplock 610 and PEVA45 as profiled steel sheet and PrimaFlex dry board for surface sheathed. All 12 wall panel samples have been tested under axial load until failure. From the experiment, it was found that the maximum load capacity of PSSDB wall panel can withstand is 1329kN with PEVA45 at screw spacing of 200 mm. While for the wall panel assembled using Cliplock 610, the maximum load is 612kN. The study shows that the new PSSDB wall panel system has a great potential to be used as a load bearing under axial load and expected to have a confidence for structural system in future construction.

Abstract: This paper reports the fire resistance property of a lightweight aggregate geopolymer concrete (LWAGC) material synthesized by the alkali-activation of locally source fly ash (FA) after exposed to elevated temperatures ranged of 100 °C to 800 °C. The results illustrates that the concrete gained a compressive strength after exposing to elevated temperatures of 100, 200 and 300 °C. Afterward, the strength of the LWAGC is started to deteriorate after exposing to elevated temperatures ranged of 400 °C to 800 °C, due to the difference in thermal expansion between the geopolymeric paste and LWA as well as to the evaporation of the structural water which increased the thermal shrinkage.

Abstract: 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.

Abstract: This paper presents the results of investigation on structural behavior of the load bearing walls of interlocking bricks system called Brickcool. The model of Brickcool load bearing walls with and without reinforcement were tested in the laboratory until they failed. Both models were prepared with the same dimension of 1.3 m height, 1.0 m wide and 125 mm width. The influence of reinforcement on the deflection and strain of the load bearing walls were examined. Physical and mechanical tests of the individual brick were also been carried out. Results of this study proved that the model of load bearing wall with reinforcement have higher failure load with lower displacement at the top of the wall. The presence of reinforcement in strengthening the wall panel also increase the compression and tension strain compared to the wall panel without reinforcement. The physical and mechanical test results also found that the bricks have satisfied the minimum requirement values set by the British and American Standards.

Abstract: This paper is focused on behavior of fiber reinforced cement composites (FRC) and ultrahigh-performance fiber reinforced cement composites (UHPFRC) in dependence on the direction of casting. Twelve prismatic samples of size of 400 x 100 x 100 mm were cast into moulds; six of these were FRC and the other six were UHPFRC. Three samples of both series were cast in the common horizontal direction and the other three in the vertical way. It was found that fracture energy of horizontally cast prisms was approximately three times higher in both cases than the vertically cast ones. The peak loads of FRC were very similar for both ways of casting. On the other hand the UHPFRC behaved differently, the peak load of horizontally cast prisms was approximately 2,5 times higher than the vertically cast ones. It was demonstrated that these differences are caused by the way of casting and vibration.