Environmentally Friendly Material: Coconut Husk Ash and Fly Ash as Supplementary Cementitous Material

Concrete is the main material in the construction industry. Concrete is consisted of binder and filler. The main concrete binder is cement paste. The cement industry nowadays is not environmentally friendly because of the burning of cement raw materials require energy up to 1450°C. On the other hand, cement compound content which can be utilized as the environmentally and friendly subtitution is Silica (SiO2) and material with pozzolan character. The resulting product is a calcium silicate hydrate (CSH). This study used coconut husk ash and fly ash as a pozzolan material. In order to confirm the coconut husk ash and fly ash can be used as a pozzolan material, study used compressive strength method test on the cement paste hydration ages of 3 and 7 days. Results of this study suggested that the optimum composition of coconut fiber composite waste and fly ash managed to substitute 30% by weight of cement with the composition: 25% coconut husk ash and 5% fly ash.