Curing duration of high performance concrete

Abstract EN

The objective of this experimental work is to evaluate the minimum curing duration of high performance concrete which has a direct impact on construction rate and economy.

The exploratory study summarized the influence of the duration of moist curing on the variation of strength with distance from the drying surface.

The strength at an age of 28 days was used as the basis for comparison.

Six concrete mixtures with water / cementitious materials ratios 0.35 and 0.47 and two different cementitious materials (silica fume and fly ash) were used.

The former water / cementitious materials ratio is intended to be representative of the hydration and drying behavior of a high–performance concrete with a low water / cementitious materials ratio.

Four moist curing periods were adopted.

At the end of the moist–curing period, the specimens were sealed and allowed to dry at 25 C and 60% relative humidity.

Tensile strength was measured at 28 days as a function of distance from the drying surface using cylindrical test specimens with circular notches cast at various depths (15, 25 & 55 mm).

The notches created reduced cross sections that forced failures to occur at predetermined distances from the drying surface.

Relationships between tensile strength and depth from drying surface were compared with those of specimens continuously moist cured.

The experimental results showed interesting results with respect to the duration of curing which may be sufficient to ensure adequate strength development.