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%.