Effect of Polypropylene Fibre Addition on the Physical and Mechanical Properties of Sandcrete Walling Units
*Hamisu, S., Khalil, I. M. and Ibrahim, A. G..
Department of Building, Ahmadu Bello University, Zaria, Kaduna, Nigeria.
DOI: 10.36108/laujoces/6202.61.0222
Abstract
Hollow Sandcrete Blocks are walling units made from a mixture of cement, sand (fine aggregate), and water. However, these blocks are characterized as brittle units, having low tensile strength and therefore highly susceptible to failure. The study focused on evaluating the effect of Polypropylene (PP) fibre on the characteristics of sandcrete walling units with a view to overcoming the shortcomings associated with it. Here, the PP fibre used in the sandcrete mixes was at 0, 0.1, 0.2, 0.3 and 0.4% by weight of dry materials. Properties evaluated were those of flow-ability, compressive and flexural strengths, and density and abrasion resistance. Sandcrete Walling Units specimens were produced; the specimens were 50 × 50 × 50 mm mortar cubes and 160 × 40 × 40 mm mortar beams. Results indicate improvement in flow-ability by 5.6% with 0.2% PP fibre addition. Incorporation of 0.1% PP fibre exhibits an increase in compressive strength by 9% and flexural strength by 3% compared to the control. The density consistently decreases with an increase in fibre content; it was 2066 kg/m3, 1999 kg/m3, 1807 kg/m3, 1688 kg/m3 and 1573 kg/m3 for 0, 0.1, 0.2, 0.3 and 0.4% respectively. For abrasion, 0.1% and 0.2% fibred specimen exhibit higher resistance capacity to abrasion, which is 57% and 79% higher compared to the control. While 0.3% and 0.4% fibred specimens demonstrated lower resistance of 121% and 139% compared to the control. As such, the study established that incorporating PP fibre in sandcrete walling units enhance both mechanical and durability properties. Therefore, a polypropylene fibre addition of 0.1 – 0.2% by weight of mortar was recommended for sandcrete walling units’ production.
Keywords: Fibre, Polypropylene, Sandcrete and Walling Units.