Title: Quality Control of Concrete by Means of Short-Termed Tests at La Angostura Hydroelectric Project, State of Chiapas, Mexico
Author(s): Manuel Mena Ferrer
Publication: Symposium Paper
Appears on pages(s): 51-74
Keywords: accelerated tests; compressive strength; concretes; dams;
fresh concretes; hydration; quality control; spillways; water-cement
During the construction of La Angostura Hydroelectric Pro-ject, owned by Comision Federal de Electricidad (CFE) of Mexico, quality control of concrete has been achieved by means of short-termed tests, in addition to the standard 28-day tests. Two types of short-termed tests were performed: analysis of fresh concrete samples according to a non-standardized method devel-oped at the laboratories of CFE, and autogenous curing compressive strength following Procedure C of ASTM Designation C 684. This paper presents the results obtained in these tests after a three-year period of application at the job site; they have been ana-lyzed statistically and correlations among them are discussed. It was concluded that fresh concrete analysis tests were rea-sonably accurate to determine the actual composition of freshly mixed concrete, but the results did not allow the prediction of the 28-day concrete strength, because of influence of changes in cement charac-ter: istics. The autogenous curing strength test represented a good means to predict the 28-day concrete strength for all types of mixes, save for 3-in. maximum aggregate size, possibly due to wet sieving.