Analisis Kuat Tekan dan Serapan Air Paving Block dengan Pemakaian Fly Ash sebagai Pengganti Sebagian Semen

Concrete brick (paving block) is a building material composition made from a mixture of portland, water, and aggregate cement with or without other additives that does not reduce the quality of concrete bricks. Fly ash is a by-product of burning from coal. Fly ash when disposed of openly can cause contamination because fly ash contains several toxic elements such as arsenic, vanadium, antimony, boron and chronium. Fly ash so as not to contaminate the environment can be used as a partial replacement of cement. Therefore, the study was conducted by using fly ash to mix on paving block as a substitute for cement. In this research using percentage of fly ash variation 0%, 10%, 15%, 20% of cement weight. The analysis review on this research is compressive strength and water absorption, the test object is a cube with size 6cm x 6cm x 6cm. After testing and research, it is found that the use of fly ash can increase the compressive strength of paving block with the addition of fly ash less than 15% and decrease in addition of fly ash more than 15%. Optimum paving block strength is found in fly ash variation of 15% that is 97,92 kg / cm2 or increase 15,10% from normal paving. Addition of fly ash 0%, 10% and 15% fulfill water absorption value less 10%, so it qualifies for paving block while 20% fly ash addition is not eligible for paving block. Keywords : paving block, fly ash, compressive strength, water absorption