Characterization of Clayey Soils from Congo and Physical Properties of Their Compressed Earth Blocks Reinforced with Post-Consumer Plastic Wastes

Abstract

Physical properties of compressed earth blocks reinforced with plastic wastes are compared to those of nonreinforced ones. These bricks are made with two clayey soils from two deposits of Congo located in Brazzaville and Yengola. Mineralogical and geotechnical analysis revealed that the soil of Brazzaville is mainly composed of <i>kaolinite</i> whereas that of Yengola is a mixture of <i>kaolinite</i> and <i>illite</i>. The amounts of clay (46 and 48%, respectively) are higher than those usually recommended for bricks’ production without stabilizers. Despite this difference of mineralogical compositions, the physical properties of these soils are quite similar. The compressive strength of the resulted bricks compacted with an energy of 2.8 MPa is about 1.5 MPa, which is the lower limit value allowed for adobes. Reinforcing with polyethylene waste nets increased the strength by about 20 to 30% and slightly enhanced resistance to water, Young’s modulus and strain to failure. However, the reinforcement had no significant effect either on bricks’ curing length or on their shrinkage

Effect of Polypropylene Fiber Length on the Flexural and Compressive Strength of Compressed Stabilized Earth Blocks

“…On the basis of ecological metrics, natural fibers are preferable for CSEB reinforcement because of their being derived from renewable resources that are generally readily available at affordable costs. However when untreated, the fibers may have a negative impact on the mechanical properties of matrices (Elenga et al 2011). The highly alkaline environment created through OPC hydration degrades untreated fibers, which negatively affects the durability of concrete (ACI 544.1R, 1996).…”

“…Studies investigating these parameters use both natural and synthetic fibers. It has been demonstrated that sisal (Namango 2006), coconut fiber (Khedari et al 2005;Obonyo, 2011), straw (Binici et al 2005), polyethylene (Elenga et al 2011) can all be feasible options. On the basis of ecological metrics, natural fibers are preferable for CSEB reinforcement because of their being derived from renewable resources that are generally readily available at affordable costs.…”

Earthen construction materials: Assessing the feasibility of improving strength and deformability of compressed earth blocks using polypropylene fibers

“…Fiber-reinforced blocks can withstand higher stresses by absorbing high amounts of energy making them particularly important in earthquake prone regions [8]. It has been demonstrated that sisal [11,12], coconut fiber [13][14][15], straw [16], polyethylene [10], jute [17,18], are all feasible options for CEB reinforcement. Improvement in ductility is widely accepted as a key benefit of fiber reinforcement in soil-cement composites.…”

“…Both natural (obtained from plants and animals) and synthetic fibers are used to reinforce soils for CEB production [7]. The inclusion of fibers into soil-cement mixes for CEB production creates a network of fibers, which improves tensile and shearing strengths, and also helps reduce shrinkage [7][8][9][10]. Fiber-reinforced blocks can withstand higher stresses by absorbing high amounts of energy making them particularly important in earthquake prone regions [8].…”

Investigation of the Effects of Different Natural Fibers on the Strength of Compressed Stabilized Earth Blocks (Cseb)

“…To further improve its mechanical properties and, at the same time, reduce waste, researchers are reinforcing it with natural fibers as they show a significant result in post-peak load deformation behavior. The use of fiber reinforcement into CSEB production creates a network of fibers that prevents cracking of the soil resulting from shrinkage and improves tensile and shearing strengths [2], [3]. The inclusion of fibers into CSEB results to resistance towards higher stresses by absorbing high amounts of energy, making them particularly important in earthquake prone regions [4].…”