Laboratory study to evaluate the mechanical properties of concrete mixtures under the influence of hot climate (Desert)

Abstract

Concrete is the main material for implementing concrete buildings and infrastructure projects in most regions of the world. During the past years, it has witnessed a great development that contributed to the construction of concrete buildings of various types ]1[ .Despite the development witnessed by the stages of concrete manufacturing, there are still some problems facing the stages of its implementation. This research reviews the study of the effect of hot climate (desert) on the mechanical properties of concrete mixtures, which included of compressive strength, indirect tensile strength and bending strength by doing laboratory tests were conducted on ordinary concrete with comparison with the test results of improved concrete added to silica fume and superplasticizers during (0, 45, 90) daily thermal cycles. The study used ratio of additives in the normal mix (cement: aggregate: sand: water) is (1: 2.5: 2: 0.55) % of the cement weight and the ratio of additives in the improved mix (cement: aggregate: sand: water: Sika Fume: superplasticizers) is (1: 2.2: 1.3: 0.22: 0.1: 0.18) % of the cement weight. After the mixing process, the samples were immersed in water for 28 days and then placed in electric ovens for (45, 90) thermal cycles. Then, the compressive strength test, indirect tensile strength test and flexural strength test were conducted for the normal mix and improved mix samples.The compressive strength of the improved concrete recorded much better values than the compressive strength values of the normal concrete during all stages of the thermal cycles. Also the results of indirect tensile strength reflected a significant advantage for the improved concrete over the normal concrete during all stages of the daily thermal cycles. More over the test results rapture stress showed that the improved concrete has better resistance to bending comparing with the bending resistance of normal concrete during the daily thermal cycles. The process of adding improved materials to the concrete mix reflected achieving amazing properties by developing the concrete’s behavior in resisting loads and hot climatic conditions.