Highway Research Record

VI. RESEARCH WORK DONE IN ACADEMIC INSTITUTIONS RELATED TO THESIS WORK
B. PAVEMENT ENGINEERING AND PAVING MATERIALS
Effect of Aggregate Shape on Concrete Mix Properties

Date of Start:May 2004
Indian Institute of Technology, Kharagpur (S, I)

Scope and Objectives
(i) To determine the Flakiness index and Elongation index (total) of the available coarse aggregate.
(ii) To determine the effect of varying F.I. & E.I. on concrete mix properties like flexural strength, compressive strength and      workability of the concrete.
(iii) To find out the optimum percentage of combined F.I&E.I on the basis of above findings.
(iv) To determine the effect of rounded and crushed-rounded aggregate on concrete mix properties like flexural strength,       compressive strength and workability of the concrete.
(v) To design the thickness of the concrete pavement as per IRC: 58-2002 by using the above different shapes of flexural      strength and carry out the cost analysis.

Methodology
Experimental study on the effect of aggregate shape on concrete properties like compressive strength, flexural strength and workability of concrete was carried out.

Findings and Conclusions
(i) Avoiding flaky and elongated particles as per IS:383 is not really necessary and up to 50% combined index can be used with    out substantially affecting strength
(ii) Crushed rounded aggregates are definitely preferred and so should be used whenever available locally.