Effect of polycarboxylate superplasticizers on large amounts of fly ash cements

Abstract

This study analyzes the interaction between polycarboxylate superplasticizers and cements with large amounts of high porosity fly ash. The analysis was performed with two polycarboxylate superplasticizers: a liquid commercial polycarboxylate with polyoxyethylene side chains (LPC) and an experimental solid polycarboxylate (SPC).The conclusions confirm that the use of these types of superplasticizers improves cement behavior, increasing fluidity and decreasing the water demand of cement products. LPC is slightly more effective than SPC. With regard to hardened performance, SPC provides cement mortars with a denser structure which leads to higher compressive strengths and lower water absorption capacity than in both mortars containing cement without superplasticizer and the mortar with LPC. The best performance was had with a dose of 0.15% SPC.