Analysis of Chemically Activated Zeolite as a Partial Cement Replacement in Self Compacting Concrete with Varying Water to Cement Ratios

Abstract

As time progresses, concrete has undergone innovations to address existing challenges. One
such innovation is Self-Compacting Concrete (SCC), which incorporates superplasticizer
additives, enabling the concrete to flow and achieve relatively high compressive strength. The
aim of this study is to analyze the effect of the water-cement ratio (WCR) on the workability
of self-compacting concrete and its influence on compressive strength. A quantitative method
with an experimental approach was conducted in a laboratory, utilizing zeolite activated with
1M NaOH at varying FAS levels from 0.29 to 0.37. Fresh concrete tests, including v-funnel,
slump flow, and l-box, were performed following SNI 7656-2012 standards. The compressive
strength test results for WCR variations of 0.29, 0.31, 0.33, 0.35, and 0.37 were 42.71 MPa,
41.58 MPa, 40.82 MPa, 40.35 MPa, and 40.26 MPa, respectively. An increase in the WCR
value from 0.29 to 0.37 resulted in a gradual decrease in compressive strength due to a
reduction in materials such as cement, zeolite, and superplasticizer, alongside an increase in
water content. This condition enhances the porosity of the concrete, leading to lower density
and compressive strength. Concrete with a low WCR has smaller and denser pores,
optimizing the pozzolanic reaction between zeolite and cement, thereby improving the
structural strength of the concrete. These findings align with previous research. In
conclusion, the results demonstrate that a lower WCR corresponds to higher compressive
strength, while concrete with a higher WCR exhibits good self-compacting concrete
characteristics.