Paper Title
Comparative Study on Proportion of Hollow Concrete Block to its Compressive Strength

Wall as one of non-structural parts in a building is usually considered to be light material based. Concrete block and clay block are still chosen to be one of the most selected materials so that the strength can be fulfilled to support the loading even though the self weight of the wall cannot be considered light at last. However, concrete hollow block had been one of the solutions to fulfill both strength and weight in Indonesia since many earthquakes attacked for recent years. The absence of clear requirements on SNI 03-0349-1989 for gaining certain quality of hollow concrete block had created many failures in trial for reaching the target compressive strength. This paper will do comparative study on the proportion of hollow concrete block in order to help the producer, researcher, and public to get the target strength easily (Quality I of required compressive strength) based on the determination of fine aggregate quality and water cement ratio. The proportion of cement and fine aggregate was selected to be 1:1 to 1:6 and 0.5 for water cement ratio. The result refer that the proportion or 1:5 (cement to sand) was the minimum proportion to reach the no. 1 quality compressive strength target of hollow concrete block. Meanwhile, the absorption can be handled accurately below 25 per cent for the whole comparative proportion tested until the proportion of 1:6 (cement to sand). Keywords- Hollow Concrete Block, Compressive Strength, Water Cement Ratio, Absorption.