| Abstrakt: |
Mount Sinabung is one of the active volcanoes in Indonesia located in Karo Regency, North Sumatra. Since the first eruption on August 27th, 2010, Mount Sinabung still emits smoke and volcanic ash. The utilization of Sinabung volcanic ash waste (AGS) has not been carried out optimally. Researchers tried to use it as cement substitution materials in the manufacture of paving blocks. Lime (Ca+) was added intothe paving block mixture to cover the lack of CaO composition from Sinabung volcanic ash. Tha paving block mixture materials generally consist of cement, sand, and stone ash. The paving blocks design used in this research was made with a mixture ratio of cement: sand: stone ash, which was 1:2:3. Sinabung volcanic ash and lime were added to this mixture as the substitute materials. The addition of that material was conducted by reducing the percentage of cement weight and varying the composition ratio used according to the volume ratio category of constituent aggregates, namely 0%, 5%, 10%, 15%, 20%, and 25 % of Sinabung volcanic ash and lime by weight of cement. The manufacture of specimens and quality testing procedures were in following with Standard Nasional Indonesia (SNI 03-0691-1996). The results obtained from the addition of lime and Sinabung volcanic ash were as follows: The average compressive strength for a mixture of 0% AGS+25% K is 34.07 Mpa, 5% AGS+20% K is 43.30 Mpa, 10% AGS+15% K is 44.55 Mpa, 15% AGS+10% K is 45.80 Mpa, 20% AGS+5% K is 43, 23Mpa, and 25% AGS+0% K is 33.36 Mpa. From these results, it can be concluded that the addition of lime and Sinabung volcanic ash increases the compressive strength, and paving blocks quality A is obtained in all mixtures. [ABSTRACT FROM AUTHOR] |
