Effect of some types of superplasticizers on workability and compressive strength of cement concrete

Abstract

This paper presents effect of changing superplasticizers (different chemical compound such as Sulfonate naphthalene formaldehyde-SNF, Lignosulphunates-LSF and Polyacrylate) on compressive strength and workability of cement concrete using Hoang Thach cement commonly used in the North of Vietnam. Experimental results show that the workability and compressive strength at different ages of cement concrete using different superplasticizers such as Sikament NN (based on SNF), Sikament R4 (based on LSF), Rheobuild 561 (based on Polyacrylate) with the same dose (0.8 l/100kg of cement PCB30) showed a difference. The slump of concrete using Silikament NN was the highest, while Rheobuild 561 was the lowest. The compressive strength at 28-day age of concrete using Rheobuild 561 was the highest, while using Silikament NN was the lowest. Therefore, it is necessary to check the compatibility of cement and superplasticizer admixtures before concrete production for choosing the type of admixture used in accordance with specific purposes and requirements.