Title:
Reproportioning Concrete Mixes
Author(s):
T. S. Nagaraj, S. G. Shashiprakash, and B. K. Raghu Prasad
Publication:
Materials Journal
Volume:
90
Issue:
1
Appears on pages(s):
50-58
Keywords:
aggregates; cements; compressive strength; mix proportioning; water-cement ratio; workability; Materials Research
DOI:
10.14359/4020
Date:
1/1/1993
Abstract:
Integral to concrete mix proportioning are preparing trial mixes and balancing such factors as reasonable economy against placement, strength, and durability requirements. It is necessary to determine the water-cement and aggregate-cement ratios to satisfy workability requirements and obtain the target 28-day compressive strength. There is no direct, simple method by which the characteristics of cement, namely, fineness and chemical composition, can be considered in proportioning concrete mixes. Based on the physicochemical interactions in the cement-water system, a generalized approach for proportioning concrete mixes has been developed. Trial mix details (water- cement and aggregate-cement ratios) are derived based on any of the accepted methods for proportioning concrete mixes. The workability (compacting factor) and 28-day compressive strength reflect the physicochemical characteristics of cement and form the basis for reproportioning mixes. Based on this data, the final mix is proportioned using the three equations reported in this paper. This method can also be used to obtain a set of concrete mixes with wide ranges of workability and strength.