Critical Comparative Study of OPC Based & PPC Based Nominal Mix Concretes

Abstract

This paper deals with assessing suitability of PPC for making of nominal mix concrete as per provisions in clause no. 9.3, table 9, p. no.23  of I.S. 456 -2000. For an internal study at Maharashtra Engineering Research Institute Nashik, three types of concrete specimens were cast in the laboratory with three nominal mix proportions (as per clause no. 9.3, table 9, p. no.23  of I.S. 456 -2000) using OPC 43 conforming to IS 8112 – 1989. Likewise, exactly three similar types of concrete specimens were cast in the laboratory with three similar nominal mix proportions (as per clause no. 9.3, table 9, p. no.23 of I.S. 456 -2000) using PPC conforming to IS 1489 (Part 1) - 1991. Apart from this, two more concrete specimens of higher grades were cast in the laboratory using OPC 43 as the binder. Likewise, exactly two similar concrete specimens of higher grades with similar mix proportions were cast in the laboratory using PPC as the binder. Thus, equal opportunity was given to OPC 43 & PPC for all five sets of concrete specimens.  Compressive strengths at various ages were observed for each concrete specimen.  Also, flexural strength at 28th day was observed for every concrete specimen. Comparative study reveals that PPC is not suitable for making of nominal mix concrete as per present norms of I.S. 456 because PPC is not producing the concrete of the desired/required strength. Hence, the relevant norms of I.S. 456 – 2000 need amendments.