Characterization of light foamed concrete containing fly ash and desulfurization gypsum for wall insulation prepared with vacuum foaming process

Geopolymer is a new development in the world of concrete which cement is replaced by pozzolanic materials such as fly ash and activated by an alkali activator. Alkali activator will act as a binder in concrete mixtures. An exposure condition of seawater to the geopolymer concrete is significant to be studied since the properties of concrete will be affected especially exposure to an aggressive environment. The aim of this study is to evaluate the durability of fly ash-based geopolymer concrete in seawater exposure, then compared to ordinary Portland cement (OPC) concrete. The ratios of fly ash to alkali activator (FA/AA) and sodium silicate to sodium hydroxide (Na2SiO3/NaOH) were fixed as 2.0 and 2.5, respectively. The concentration of NaOH used was 12M. The fly ash will be mixed with alkali activator until homogeneous. After moulding process, the sample of concrete will be immersed in seawater for 7, 14, 21, 28 and 60 days. The results showed that the density of geopolymer concrete was higher than OPC concrete. The water absorption for 60 days of curing showed the geopolymer concrete was 0.9%, meanwhile OPC concrete achieved 8.3%. The different percentage of weight loss test for geopolymer concrete and OPC concrete was 1%. The compressive strength for geopolymer concrete was reported as higher than OPC concrete.

Performance of fly ash based geopolymer concrete in seawater exposure

Huge quantities of Palm Kernel Shell (PKS) are produced as wastes annually due to increase in demand for palm oil. Regardless of the numerous potential derivatives from the waste PKS such as activated carbon, pulverized shells, liquified fumes etc., there still exists the problem of its indiscriminate disposal or incineration without energy recovery thereby creating both economic and environmental concerns. This review is therefore aimed at presenting the state of the art on the numerous applications of PKS as a carbon–neutral, biodegradable, affordable and available residual component of oil palm processing, which if properly maximized will be a value-added precursor to solving the associated disposal and environmental challenges. Findings from most studies demonstrate that PKS has great potentials as a bioabsorbent, abrasive, detoxifier, antibacteria, antifungi and antioxidant material as well as a biofuel for syngas and biodiesel production. Other applications of PKS include reinforcement for polymer and metallic composites and aggregates in construction and ceramics. Industrial uses of PKS in agriculture, oilrefining, healthcare, fashion, glass, drugs and rubber vulcanizate production were also discussed. The suitability of PKS for other engineering applications were also highlighted with recommendation for further exploitation suggested. This review is expected to provide technical data for both scientists and policy makers in environmental sustainability. 

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Potentials of Palm Kernel Shell Derivatives: A Critical Review on Waste Recovery for Environmental Sustainability

Palm Kernel Ash and Eggshell Ash as Partial Replacement of Cement in Interlocking Brick Production

A concrete which cement is totally replaced by source material such as fly ash and activated by highly alkaline solutions is known as geopolymer concrete. Fly ash is the most common source material for geopolymer because it is a by-product material, so it can get easily from all around the world. An investigation has been carried out to select the most suitable ingredients of geopolymer concrete so that the geopolymer concrete can achieve the desire compressive strength. The samples were prepared to determine the suitable percentage of palm kernel shell used in geopolymer concrete and cured for 7 days in oven. After that, other samples were prepared by using the suitable percentage of palm kernel shell and cured for 3, 14, 21 and 28 days in oven. The control sample consisting of ordinary Portland cement and palm kernel shell and cured for 28 days were prepared too. The NaOH concentration of 12M, ratio Na2SiO3 to NaOH of 2.5, ratio fly ash to alkaline activator solution of 2.0 and ratio water to geopolymer...

Ang Zhi Jian

Papers

Performance of fly ash based geopolymer incorporating palm kernel shell for lightweight concrete