Experimental study of hybrid concrete blocks based on sawdust and calcined clay using cement as a binder

The use of sawdust and calcined clay in the production of load-bearing concrete blocks has been minimally studied, while recent research has focused on incorporating other materials, yielding limited results. This study specifically examines the production of hybrid concrete blocks using sawdust (S) and calcined clay (CC), with cement (CEM) as the binder. combinations of S and CC were used as weight-based additives to the concrete block in varying S/CC ratios of 3:3, 3:5, 3:10, 5:3, 5:5, and 5:10, with cement serving as the binder for the hybrid blocks. A total of 412 samples were designed following ACI 211.1 standards, with dimensions of 12 cm wide, 39 cm long, and 19 cm high. Laboratory tests included the determination of density, absorption, warping, dimensional variation, and compressive strength in units, prisms, and shear testing in masonry walls. The results showed significant variations: density fluctuated between -2.31% and 7.61%, while absorption ranged from -44.03% to 69.03%. The warping and dimensional variation tests remained within normative parameters. Regarding mechanical properties, compressive strength decreased by 5.77% in units, 2.74% in prisms, and 2.08% in masonry walls for the 3S:5CC sample; however, it remained within local normative limits. It is concluded that the production of hybrid concrete blocks using sawdust and calcined clay is feasible, as they meet the requirements for use as structural masonry units. Furthermore, these blocks contribute to a better utilization of these waste materials and environmental protection. Their gradual adoption in the construction industry is recommended, as further in situ experimental testing is conducted.