Mechanical-Damage Behavior of Mortars Reinforced with Recycled Polypropylene Fibers

Abstract

Commercial polypropylene fibers are incorporated as reinforcement of cement-based materials to improve their mechanical and damage performances related to properties such as tensile and flexural strength, toughness, spalling and impact resistance, delay formation of cracks and reducing crack widths. Yet, the production of these polypropylene fibers generates economic costs and environmental impacts and, therefore, the use of alternative and more sustainable fibers has become more popular in the research materials community. This paper addresses the characterization of recycled polypropylene fibers (RPFs) obtained from discarded domestic plastic sweeps, whose morphological, physical and mechanical properties are provided in order to assess their implementation as fiber-reinforcement in cement-based mortars. An experimental program addressing the incorporation of RPFs on the mechanical-damage performance of mortars, including a sensitivity analysis on the volumes and lengths of fiber, is developed. Using analysis of variance, this paper shows that RPFs statistically enhance flexural toughness and impact strength for high dosages and long fiber lengths. On the contrary, the latter properties are not statistically modified by the incorporation of low dosages and short lengths of RPFs, but still in these cases the incorporation of RPFs in mortars have the positive environmental impact of waste encapsulation. In the case of average compressive and flexural strength of mortars, these properties are not statistically modified when adding RPFs.

Durability of Concrete Structures with Sugar Cane Bagasse Ash

“…e effects of by-products' usage and waste materials as supplementary cementitious systems have been also extensively investigated [16][17][18][19][20][21][22][23][24][25][26][27][28][29]. As a result, fly ashes [21,27], metakaolin [30], geopolymers [31,32], slags (such as steel slags) [24,25], and sugar cane bagasse ash [33][34][35][36] were added to green concrete. e sugar cane bagasse ash is a byproduct resulting from factories' sugar and alcohol boilers [33][34][35][36].…”

Mechanical and damage similarities of adobe blocks reinforced with natural and industrial fibres

“…Yet, similar values of CWWR of adobes reinforced with industrial fibre at 1% dosage can be achieved with higher dosages (2%) of vegetal and animal fibres. Also, the industrial nature of micro polypropylene fibres makes them less appealing than natural fibres, because of the higher CO 2 emissions generated by the manufacturing of polypropylene [30]. Animal fibre had the best performance in terms of CWWR with an average value for A 2-30 of 87%.…”

“…The impact strength test setup used in this study (Figure 4), consists of a projectile released from a specific height that impacts to the centre of a specimen, as suggested by ARAYA-LETELIER et al [17,28]. The values obtained from the impact strength test can be considered as an indirect measure of the material toughness [27,29,30]. To evaluate the impact strength, the number of blows needed to fracture the specimen was counted, calculating the fracture energy with Equation 5.…”

Biopolymer-Waste Fiber Reinforcement for Earthen Materials: Capillary, Mechanical, Impact, and Abrasion Performance

“…As mentioned by previous studies (e.g., [ 58 , 59 , 60 , 61 ]), the fracture toughness of composite materials, including earthen mixes, can be modified due to fiber-reinforcement and the impact strength test has been suggested as a way of measuring this damage-absorption capacity. This research implemented a setup consisting of beam specimens supported at two points by a metallic base (20 cm distance between supports) and a metallic projectile was thrown at the midspan of the beam specimens at increasing heights (see Figure 6 ).…”