DETERMINATION OF THE UNIFORMITY OF MIXING OF PORTLAND CEMENT AND BITUMINOUS CONCRETE FOR VARIOUS MIXING TIMES BY THE USE OF RADIOISOTOPES. Annual Report No. 1, December 1, 1960 to March 31, 1961 (Final Technical Report for That Phase of the Program Dealing with Portland Cement Concrete)
Uniformity of mixing is a good criterion by which to judge the quality of a concrete mix and mixing adequacy. Cement content of mortar, fineness modulus of the aggregate, ultimate compressive strength, and visual inspection of mixing quality were used to indicate uniformity. With the exception of cement content, all determinations of the physical characteristics of the concrete were made by conventional tests as specified by the American Society of Testing Materials. Cement content of the concrete mortar was determined by neutron activation analysis of Ca/sup 49/ produced in the Ca in the portland cement. This method of cement content determination proved very feasible and could be used to predict the cement content within approximately 10% of its true value 95% of the time. Mixing time, batch replication, and position in the concrete mixer generally did not have significant effect upon cement content, fineness modulus, and compressive strength for mixers studied. Mixing times varying from 30 to 180 sec were used in evaluating uniformity of mixing. (auth)
- Research Organization:
- Georgia Inst. of Tech., Atlanta. Engineering Experiment Station
- NSA Number:
- NSA-15-031073
- OSTI ID:
- 4840677
- Report Number(s):
- SRO-47
- Country of Publication:
- United States
- Language:
- English
Similar Records
Superplasticized Portland cement: Production and compressive strength of mortars and concrete
Lignite fly ash as a partial replacement for Portland cement in concrete. Final report