No abstract

The use of waste aggregates simultaneously with expanded clay to obtain lightweight masonry mortars in construction constitutes a good way for a more sustainable society. This research presents a study about the physical properties of the mortars fabricated with construction and demolition wastes and expanded clay as lightweight material by way of flexural and compressive strength, porosity and surface abrasion resistance. Computerized tomography and microporosity show a good distribution of materials and pores. The paper also contains an analysis of the influence in the durability after incorporating different proportions of recycled aggregates. The results indicate that the properties do not suffer significant changes in external appearance after accelerated aging tests as thermal shock, saline solution, freeze and thaw, resistance to SO2 and carbonation. No flaking, cracking, splitting or cracks in the specimen's outer surfaces being observed. Therefore, it can be confirmed that the masonry mortars tested performed well in all cases when exposed to external climatic atmospheres according to the international standards.

The investigation reported in this paper is an evaluation of the mechanical behavior of full-scale ecological mortar slabs manufactured with a mixture of expanded clay and recycled concrete aggregates. The composite mortars form a compressive layer over laminated wooden joists to form a single construction unit. To do so, full-scale flexural tests are conducted of the composite laminated wood-ecological mortar slabs with different types of mortar designs: reference mortar (MR), lightweight mortar dosed with recycled concrete aggregates (MLC), and lightweight mortar dosed with recycled mixed aggregates (MLM). The test results showed that the mortar forming the compression layer and the laminated wooden joists worked in unison and withstood a higher maximum failure load under flexion than the failure load of the wooden joists in isolation. Moreover, the laboratory test results were compared with the simulated values of the theoretical model, generated in accordance with the technical specifications for structural calculations contained in the Spanish building code, and with the results calculated by a computer software package. From the analysis of the results of the calculation methods and the full-scale laboratory test results, it was concluded that the safety margin yielded by the calculations validated the use of those methods on this type of composite slab. In this way, a strong mixed wood–mortar slab was designed, contributing little dead-load to the building structure and its manufacture with recycled aggregate, also contributes to the circular economy of construction materials.