ALTERNATIF PENGGUNAAN LIMBAH PABRIK KERTAS SEBAGAI PENGGANTI SEBAGIAN SEMEN (CEMENTITOUS) DALAM PEMBUATAN BETON

Abstract

The demand of cement in construction industry is increasing. The cement price is also increasing and getting more expensive because the raw material to produce cement is not renewable material. Therefore, alternative material is required to substitute cement. The paper industry waste contains Aluminium Oxide (Al2O3), Calcium Oxide (CaO), Magnesium Oxide (MgO), Sulphur Trioxide (SO3), and Silicon Dioxide (SiO2). These compounds could be used to subtitute raw material in producing cement, and hopefully could answer this problem. This research objective is to find the influence of the use of alumunium waste in concrete, particularly the behaviour of the physical characteristics of cement paste (setting time) and mechanic characteristics of concrete (compressive strength, modulus of elasticity, bond strength of reinforcement, and modulus of rupture) with waste content 5% until 15% from the composition of cement for concrete fc’ =25 MPa. Results of research indicated that the waste was retarder and the waste content less than 10% were met the condition of SNI 15-2094-1994. The use of 5% paper mill waste in a concrete mixture still was permitted because modulus of elasticity increased by 8% compared to the concrete without waste. Furthermore, compressive strength waste concrete 5% is 26,7 MPa, where the value is above fc’= 25 MPa. Bond slip that was reached during maximum P pulled still on the minimal value permitted by ASTM C 234, and the modulus rupture (14.7%) was smaller compared to the waste concrete 10%.