Abstract:
Self-compacting cementitious system (SCCS) are emerging class of concrete materials that offer great potential for improved ease of placement, increased rate of construction and lower cost through reduced labour and time. SCCS are designed to meet the demands of specific application at various sites and highly workable system that can flow through dense reinforcement and complex structural element under its own weight without bleeding and segregation and without using any external means for compaction. The above mentioned properties of SCCS are achieved by using special concrete ingredients including mineral admixtures like lime stone, fly ash, granulated blast furnace slag, rice husk ash etc(known as SRMs) and chemical admixtures. The present study encompasses the evaluation of locally available secondary raw materials (SRMs) including Ground granulated blast furnace slag (GGBFS), Quarry Dust (QD) and Glass powder (GP) for the production of self- consolidating cementitious systems (SCCS). The parameters investigated in this study include particle characterization of SRMs, flow behavior, strength development, x-ray diffraction (XRD) study and microstructural analysis of Self compacting paste systems (SCP) by scanning electron microscopy (SEM). The results indicate that the microstructure and strength of SCP systems using pozzolanic SRMs depends upon the degree of pozzolanic activity of SRMs. Surface morphology, size and shape of SRMs will have a direct bearing on super plasticizer demand, flow/yield stress, viscosity and effective water content available in the mixture of SCCS. The rate of strength gain of self-compacting cementitious system is also an important aspect besides the strength level at a specified age as it varies with the type of secondary raw material being used. GGBFS and QD containing sample of SCP systems exhibited higher strength due to physical and chemical effects. After the detailed analysis of the result it can also be stated that investigated SRMs can
8
be successfully used in self-compacting cementitious systems as each contributes positively towards enhancement of certain properties of self compacting concrete.
