EFFECTS ON CONCRETE QUALITY OF FLUCTUATIONS, WITHIN SPECIFICATION LIMITS, IN COARSE AGGREGATE GRADING.
Final technical rept.,
ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS
Pagination or Media Count:
Six mass concrete mixtures were made in the laboratory, three containing natural fine and coarse aggregate and three containing manufactured limestone fine and coarse aggregate, all with the coarse aggregate graded to 6- in. maximum size. The coarse aggregate was separated into four size groups, which were then combined into three different gradings, the finest, coarsest, and middle gradings permitted by the Corps of Engineers Standard Guide Specifications for Concrete. Each grading was used for both the natural and limestone aggregate in all other respects the six mixtures were identical, with the fine aggregate grading held constant. Tests were made of both the plastic concrete and hardened concrete specimens to determine the effects of the variations in coarse aggregate grading on the properties of the concrete mixtures. The data indicated that mass concrete containing either the finest or coarsest coarse aggregate grading permitted by the specification and either the natural gravel or crushed limestone is equal in quality to mass concrete containing the middle coarse aggregate grading. The strengths of the concretes made with the three gradings had slightly different values, but statistically no significant difference was found. Author
- Ceramics, Refractories and Glass