Production and evaluation of low-density cast-wood-cement blocks for civil construction

The objective of this work was to evaluate the feasibility of the use of Pinus spp (Pinus elliotti and Pinus taeda) wood chips from the lumber industry for the production of simple low-density concrete cast blocks for internal brickwork applications. Chips previously treated in Ca(OH)2 suspension were classified by passing the 4.75 mm sieve and retaining in the 2.36 mm sieve, were used. The blocks were produced with wood:cement ratios (traces) of 1:1.5 and 1:2.2 (CP II-Z) and 1:2.2 (CP V-ARI), using the vibro-compaction process. The evaluated properties (NBR 12118-2014) were: Moisture content, apparent density, water absorption, axial compression strength and thermal conductivity. The obtained results indicated an increase in density and resistance to axial compression of the blocks with higher ratios, regardless of the type of cement. The results of thermal conductivity indicated better thermal insulation of the blocks of wood:cement compared to conventional cementitious materials. The blocks presented axial compression strength below the minimum requirement of 3.0 MPa (NBR 6136-2014) established for structural blocks. However, its production can be recommended for applications in internal brickwork, without structural function, with the substitution of mineral aggregate by vegetable (wood), with consequent reduction in product weight. © 2020 University of Sao Paolo. All rights reserved.