ANALYSIS OF THE INFLUENCE OF MINERAL ADDITIONS ON THE PROPERTIES OF SELF-HEALING CONCRETE

The sustainability of buildings represents one of the biggest problems in the civil engineering industry from the point of view of global economy and ecology. The construction of structures requires a lot of energy and non-renewable resources that generate large amounts of CO2 during their production, as well as high costs for the construction process itself. Annually, 2.5 tons of concrete are produced per person, and it is known that the main component in concrete is Portland cement. The process of obtaining the cement clinker results in the release of 1 ton of CO2 for every ton of clinker produced if the calcination emissions and the fuel required for the rotary kiln are taken into account. Taking into account the fact that in 2022 4.1×109 tons of cement were produced and the CO2 emissions from that cement were about 3×109 tons, which is assumed to be 5 – 7% of the total CO2 emissions. The current solution to this problem is to design structures with a longer lifespan, which is often overestimated due to the lack of maintenance of the structures, which leads to a shorter lifespan of the structures, and which ultimately leads to the need for new structures and thus new input energy and resource. The reason for this accelerated degradation of the structures is the biggest “enemy” of concrete, namely the cracks that are an inevitable part of it. The problem with cracks is that they represent a “shortcut” for aggressive agents that penetrates in the concrete and lead to the corrosion of the reinforcement, thus reducing the load-bearing capacity of the structure. In such cases, the ability of concrete to heal its own cracks represents a huge opportunity in the field of sustainability of structures, meaning that the structure made of such concrete has an increased lifespan and increased sustainability of the structure. It is for these reasons that in this paper the possibility of self-healing of different concrete mixes will be experimentally investigated and their self-healing efficiency will be determined by monitoring different key parameters and conducting several tests.