Thermal and structural optimization of lightweight concrete mixtures to manufacture composite slabs

The use of composite slabs in buildings is increasingly widespread in the EU in the last decades. Current standards specified the minimum concrete compressive strength used in its manufacture as 25 MPa. The aim of this work is to study different lightweight concrete mixtures to manufacture composite slabs, taking into account their thermal and structural properties, such as thermal conductivity and compressive strength. Firstly, design of experiments methodology was used to study different formulations of lightweight concrete mixtures. Secondly, a test protocol was established in order to maintain the maximum homogeneity in the samples. Thirdly, structural and thermal tests were done and the experimental results were analyzed. Results of compressive strength varies between 14.90 to 27.43 MPa and thermal conductivity are between 0.68 to 0.93 W/mK. Finally, the concrete mixtures was optimized and four were chosen as the most suitable ones for its use in this type of slabs.