Water-resistance performance analysis of Portland composite concrete containing waterproofing liquid membrane

Abstract

Portland composite cement (PCC) is well-known as a low-carbon and low-cost cement as compared to Ordinary Portland cement (OPC). Hence, PCC is broadly used for infrastructure development. The concerning issue is that PCC concrete show low strength than OPC concrete as PCC contains 30%–35% supplementary materials and 65%–70% clinker. Consequently, PCC concrete exhibits little waterproofing performance, which limits the application of PCC composites in the heavy rainy regions and design of water structures. The current research aims to improve the water-resistant quality of PCC concrete using the waterproofing chemical liquid admixture namely Sika® Membrane-2000. Different dosages of admixture like 1%, 1.5% and 2% of cement were introduced to prepare the PCC concrete compositions and examined the physico-mechanical and microstructural properties at different hydration ages. It was revealed that PCC concrete with water to binder ratio 0.40 and 1.5% admixture shown the attainment of good structural density and formation of low voids, which were closer to plain OPC concrete. In addition, water absorption was reported around 3% and 6% at 28d at static and non-static water condition, respectively for solid cube and concrete wall composed with PCC-1.5%. Moreover, CS and STS were observed about 34 MPa and 4 MPa at 28d, correspondingly which is very near to OPC specimens. Investigations of microstructures by SEM and EDS for PCC-1.5% sample also detected the compactness of hydration products and development of recognized crystals like calcium silicate hydrate, ettringite and calcium sulfoaluminate, which is corroborated with the physical and mechanical strength properties of PCC-1.5% concrete. The results of this research might be applied in the constructures works of water-resisting issue with low-cost.