In this paper, we investigate the acoustic behaviour of building elements made of concrete doped with waste-tire rubber. Three different mixtures were created, with 0%, 10%, and 20% rubber in their composition. Bricks, lattice joists, and hollow blocks were manufactured with each mixture, and three different cells were built and tested against aerial and impact noise. The values of the global acoustic isolation and the reduction of the sound pressure level of impacts were measured. Results proved that highly doped elements are an excellent option to isolate low frequency sounds, whereas intermediate and standard elements constitute a most interesting option to block middle and high frequency sounds. In both cases, the considerable amount of waste-tire rubber recycled could justify the employment of the doped materials for the sake of the environment.
The construction industry generates a considerable amount of waste. Faced with this undesirable situation, the ready-mix concrete sector, in particular, has invested energy and resources into reusing its own waste in its production process as it works towards the goal of more sustainable construction. This study examines the feasibility of incorporating two types of concrete waste, which currently end up in landfill, into the production process of ready-mix concrete: the waste generated during the initial production stage (ready-mix concrete waste), and waste created when demolition waste is treated to obtain artificial aggregate. The first phase of the study’s methodology corroborates the suitability of the recycled aggregate through characterization tests. After this phase, the impact of incorporating different percentages of recycled coarse aggregate is evaluated by examining the performance of the produced concrete. The replacement rate varied between 15% and 50%. The results indicate that recycled aggregates are, indeed, suitable to be incorporated into ready-mix concrete production. The impact on the final product’s performance is different for the two cases examined herein. Incorporating aggregates from generic concrete blocks led to a 20% decrease in the produced concrete’s strength performance. On the other hand, using recycled aggregates made from the demolition waste led to a smaller decrease in the concrete’s performance: about 8%. The results indicate that with adequate management and prior treatment, the waste from these plants can be re-incorporated into their production processes. If concrete waste is re-used, concrete production, in general, becomes more sustainable for two reasons: less waste ends up as landfill and the consumption of natural aggregates is also reduced.
The amount of ground olive stone available in Spain surpasses the needs of the construction industry for lightweight aggregate. The objective herein is to generate a material, lightweight mortar, with different percentages of ground olive stone, and then evaluate the mechanical performance and viability of these materials for the manufacture of lightweight elements used in the construction sector. To this end, an experiment was designed with nine different dosages of ground olive stone and three types of cement. In all, 378 test pieces were produced to assess the material, its handling while fresh, and its performance. Based on an analysis of consistency, density, compressive strength, and flexural strength, we were able to determine how much ground olive stone can be successfully incorporated into the material: 30% ground olive stone achieved a decrease in density of 15% compared to mortar without ground olive stone. The compressive strength of the different dosages studied remained above 70% of that of the mortar without ground olive stone. Bending behavior was more severely compromised, the values being around 50%. Cements with a more robust strength performance proved capable of assimilating a higher percentage of ground olive stone. This study shows the technical viability of the materials produced.