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This paper investigates the influence of blending of metakaolin with silica rich palm oil fuel ash (POFA) on the strength distribution of geopolymer mortar. The broadness of strength distribution of quasi-brittle to brittle materials depends strongly on the existence of flaws such as voids, microcracks, and impurities in the material. Blending of materials containing alumina and silica with the objective of improving the performance of geopolymer makes comprehensive characterization necessary. The Weibull distribution is used to study the strength distribution and the reliability of geopolymer mortar specimens prepared from 100% metakaolin, 50% and 70% palm and cured under ambient condition. Mortar prisms and cubes were used to test the materials in flexure and compression, respectively, at 28 days and the results were analyzed using Weibull distribution. In flexure, Weibull modulus increased with POFA replacement, indicating reduced broadness of strength distribution from an increased homogeneity of the material. Modulus, however, decreased with increase in replacement of POFA in the specimens tested under compression. It is concluded that Weibull distribution is suitable for analyses of the blended geopolymer system. While porous microstructure is mainly responsible for flexural failure, heterogeneity of reaction relics is responsible for the compression failure.

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Waste generation from surface coating industries brings about worsening of the environmental scenery and human health in the world. The production of these wastes is detrimental to surrounding areas in landfill or dumping spaces, therefore necessary action is required to minimize the unpleasant situation. This research is aimed at using waste generated from the manufacture of paint known as vinyl acetate effluent as an admixture in concrete. The material is rinse water taken from the cleaning process reactor. Concrete of 0% vinyl acetate effluent cured in water with those of 2.5%, 5%, 10% and 20% by weight of cement were produced and cured using Japanese standard. The specimens were tested for compressive strength, splitting tensile strength and durability at 3, 7 and 28 days. Findings show that incorporating of 2.5% of Vinyl acetate effluent improves strength properties of concrete. Higher resistance of water absorption and sulfate conditions were observed in polymer modified concrete. The study has shown that incorporating vinyl acetate effluent in producing polymer modified concrete could bring lights of using the waste material for sustainable and environmental preservations.

The use of environmentally friendly or green concrete to enable worldwide infrastructural development without increase in carbon dioxide (CO2) emission is at the focal point of the global issues concerning sustainability. Aside from the concerted efforts by the key players in the construction industry to successfully replace in part or in whole, the conventional Portland cement with green or eco-friendly cementitious materials, the challenges of ensuring that the so called green or eco-friendly concrete performs up to the required expectation has been the focus of many researches. This study therefore, provides an overview of the various processing techniques for the industrial waste materials as well as the determination of the physical and chemical characteristics of the powders prepared from the respective waste materials. The materials were characterized using BET surface area analysis, X-ray diffraction (XRD), Chemical analysis by X-ray fluorescence (XRF), 45-μm wet sieving, 75-μm and 150-μm dry sieving, Specific gravity using density bottle and reactivity index (RI). The results show that FA and PBC are very similar in terms of their physical and chemical characteristic in comparism with POFA. Notwithstanding, all the materials satisfy the basic requirements of the relevant ASTM specifications and also falls within the limit specified by ASTM C 618 for class F fly ash.