A comprehensive investigation into the effect of temperature variation on the mechanical properties of sustainable concrete

Abdulkader El Mir,Salem Georges Nehme

doi:10.1051/matecconf/201712002006

Abstract

Minimizing the production energy and resources consumption are the key principle for engineering sustainability. In the case of concrete structures, this concept can be achieved by the use of materials in the most efficient way considering in the mix design the optimal mechanical and durability properties. The substitution of ordinary Portland cement for other supplementary cementitious materials is assessing the possibility of enhancing the sustainability and decreasing the environmental impact of concrete. Mass concrete is rich in cementitious materials which results in high temperature within the concrete, hence several hazards such as cracking or temperature differences between the interior and the surface of concrete could be prevented. An experimental study evaluated on several one cubic meter sized concrete elements in which during the primary phase of hydration, the temperature variation is recorded in several location offsets with respect to time. Thermal variations results are analyzed in accordance with the cement type, CO 2 emission production of cement, compressive strength, water tightness, drying shrinkage and rapid chloride migration coefficient. The results indicate that slag cement CEM III/B 32.5, that incorporates highest amount of slag, ensured improved mechanical, thermal and durability properties in comparison with ordinary Portland cement CEM I 32.5.

Highlights

Over the few decades, the production of concrete has been growing in the less developed countries
It can be seen that at the same conditions of curing and water to cement ratio, CEM III/B 32.5 exhibited the maximum compressive strength reaching a value of 68 MPa at 56 days of age
CEM I 32.5 provided a higher compressive strength at 7 and 28 days in comparison with CEM III/A 32.5 and CEM III/B 32.5. This behavior is explained by the effect of higher clinker content developing more the hydration reaction over the slag cement type (Higher strength rate development)

Summary

Introduction

Over the few decades, the production of concrete has been growing in the less developed countries (in Asia, Africa and parts of South America). The concept of sustainability helps to improve the future of concrete production, providing encouraging potentials in reducing environmental impact. The main environmental problem in concrete production is the CO2 emission during cement creation. Substituting clinker is probably the most effective strategy to decrease the energy consumption in cement plants. For the concrete industry, when it comes to sustainability, it means providing more strength with lower emissions of CO2. In other words: more clinker made with less fuel, less implementation of cement in concrete, more strength and durability with less cement. This work was mainly based on clinker replacement by large amount of slag, fly ash or other supplementary cementitious materials, aiming for the achievement of a green concrete

Objectives

Results

Conclusion