Effect of Fineness of Continuously Graded Coarse Aggregate on Properties of Concrete

Effect of Fineness of Continuously Graded Coarse Aggregate on Properties of Concrete
Author: William O. Tynes
Publisher:
Total Pages: 37
Release: 1968
Genre:
ISBN:

Forty mass-concrete mixtures were made with natural sand, 20 containing crushed limestone coarse aggregate and 20 containing natural gravel coarse aggregate. The coarse aggregate was 6-in. maximum size and was processed into eight gradings. Tests were made to determine the degree of suitability of this presently widely used grading formula. (Author).

Effect of Larger Sized Coarse Aggregates on Mechanical Properties of Portland Cement Concrete Pavements and Structures

Effect of Larger Sized Coarse Aggregates on Mechanical Properties of Portland Cement Concrete Pavements and Structures
Author:
Publisher:
Total Pages: 172
Release: 2006
Genre: Pavements, Concrete
ISBN:

ODOT is continually searching for ways to improve the cost efficiency of Portland cement concrete without sacrificing concrete strength and stiffness. Because Portland cement is easily the most costly material used in normal concrete, limiting the amount of cement used is the quickest way to achieve cost effectiveness. In addition, limiting the cement content will also help to prevent dimensional instabilities in concrete such as shrinkage and creep. The use of larger sized coarse aggregates may be useful in limiting cement content, yet larger sized coarse aggregates may also decrease concrete strength by weakening the aggregate-cement paste bond. In many transportation structures, such as pavements, concrete strength is not critical, as dimensional stability, porosity, and durability play a more important role. It is possible, therefore, that larger sized coarse aggregates can reduce the cement content and improve these properties. Laboratory research is needed to determine if larger sized coarse aggregates can improve cement efficiency without reducing concrete strength.