Análise da influência de baixas temperaturas na resistência à compressão do concreto

Abstract

The action of the weather on the buildings cannot be avoided, as these will be frequently exposed to heat, cold, rain, wind, and other factors that affect the useful life of the buildings. However, there are many ways to reduce the effects caused by these climatic factors when the behavior of the material that faces these conditions is known. In several cities in Brazil, as well as in temperate countries, finding low temperatures is not a difficult task, therefore, samples of the most used material in the construction site, concrete, were submitted during their curing period, at a constant temperature of 5°C. It was verified that the cold is able to delay the development process of the compressive strength of the material, and this action can be clearly identified when carrying out the concrete compression tests in its early ages. When testing the concrete at three days of age, it was possible to observe that its compressive strength was approximately 15% lower, comparing to concrete cured at ambient temperature. After testing the samples with 28 days of age, another interesting fact is that the concrete exposed to low temperatures, only at its initial ages, either three or seven days, and transferred to the curing at ambient temperature, developed a compressive strength approximately 9% higher than those cured only at ambient temperature. Thus, it is understood that it’s really necessary to follow the recommendations of the standards that alert to the caution with the exposure of the concrete to the low temperatures during its initial age, either to prevent low compressive strength at it early ages, or to expect higher compressive strength at 28 days of age.