Waste Paper Ash as Partial Replacement of Cement in Concrete

Abstract

Concrete is one of the versatile and widely used building materials in the world construction industry. Cement being the main binder in concrete, its production process is both uneconomical and environmental unfriendly. In order to alleviate these problems, the use of alternative materials which have lower cost of production, lower emission of CO 2, and lower energy consumption, were being implemented. Therefore, the aim of this study is to investigate the effects of waste paper ash as cement replacement material in concrete production. Accordingly, chemical compositions of waste paper ash were investigated and cement was replaced by waste paper ash in a range of 0%, 5%, 10%, 15%, and 20%. To examine the suitability of paper ash for concrete production, its’ effect on both fresh and hardened properties of C – 25 concrete was studied. From result of this study, it was observed that, the chemical compositions of waste paper ash were not fulfill the requirements of Pozzolanic material. Paper ash has lengthened the setting times of blended cement paste and its normal consistency was increased. The cement paste with replacement up to 10% showed a normal consistency with in standard range. Workability of the concrete was tested immediately after preparing the concrete mix whereas the compressive strength tests were tested after 7, and 28 days of curing. The results indicated that workability of concrete containing waste paper ash decreases as the waste paper ash content increases. There is significant improvement in compressive strength of concrete. Replacement of ordinary Portland cement by waste paper ash up to 10% resulted in a better compressive strength than that of the convectional mix. An enhancement of 5.6% & 1.2% were observed for 5%, & 10% of replacement respectively. But the compressive strength decreases as the waste paper ash replacement increases over 10%. A highest compressive strength of 37.89kN/m2 was obtained for concrete containing 5% of waste paper ash.