Title: Strength Variations in Ready-Mixed Concrete

Author(s): A. E. Cummings

Publication: Journal Proceedings

Volume: 51

Issue: 4

Appears on pages(s): 765-772

Keywords: no keywords

DOI: 10.14359/11716

Date: 4/1/1955

Abstract:
Presents the results of a statistical analysis of the variations in crushing strength of concrete test cylinders made of commercial ready-mixed concrete delivered to a construction job. The investigation included approximately 1000 cu yd of concrete. Test cylinders were made from every batch de-ivered to the job for a period of several weeks and the 7-day and 28-day strengths were determined by crushing tests in the laboratory. The test results were then subjected to mathematical analysis by statistical methods to determine the coefficient of variation of the crushing strengths.