15 March 2001
excessive moisture, etc. Usually, once cracking has begun, continued loading will cause
additional cracks or breaks until complete failure of the pavement results.
3.2.3. Strength. Concrete pavement design is based on limiting the concrete tensile stresses
produced by applied loads. Flexural strength is used in the design of rigid pavement. Loads
applied to the pavement surface cause bending with tensile stresses at the bottom or top of the
slab and compressive stresses at the top. Since compressive strength of concrete is typically 8
to 10 times greater than the tensile or flexural strength, the ratio of load-induced tensile stresses
at the bottom of the slab to the flexural strength of the concrete controls the behavior of concrete
The relative strength as well as the durability is directly affected by: (1) quality of cement;
(2) purity of water; (3) cleanliness, durability, strength, and gradation of the aggregates;
(4) water-cementitious material ratio; (5) density of concrete; (6) amount and types of admixtures;
(7) proportioning and mixing of materials; (8) placement, finishing, and curing methods.