Influence of Urena lobata Fibre Treatment on Mechanical Performance Development in Hybrid Urena lobata: Fibre/Gypsum Plaster Composites

Abstract

Autogenous shrinkage is related to the chemistry and changes in the internal structure of the cement concrete paste on drying. This problem of drying shrinkage in early stages that occur without any moisture transfer to the surrounding environment has triggered the incorporation of fibres in the cement concrete matrix to fill the micropores and control cracking (autogenous shrinkage). This study aimed at investigating the potential use of Urena lobata (UL) fibre as microreinforcement in enhancing mechanical properties of hybrid UL-fibre/gypsum cement composites used for plasters. The fibre was harvested from the coastal region of Cameroon and treated with 0.06 M NaOH over different periods. Dispersion of treated fibre bundles in the composite (at Wt. % UL-fibre dosages of 0, 1.5, 2.5, and 3.5) was facilitated by blending with the cement paste which also helped to improve interfacial bonding between the fibre and the cement matrix. The moisture/water absorption and flexural properties within the hardened cement matrix were quantitatively assessed, and it was observed that the incorporation of treated fibre accelerated the hydration process. The test results showed an increment in compressive strength and reduction in autogenous shrinkage for the hybrid UL fibre/gypsum cement composites, while lower percentage additions (less than 2.5%) of untreated fibre appeared to have adverse effects on specimens. It was observed that properly dispersed (blended) treated UL fibres filled the fine pores in the cement matrix by providing an additional nucleation site that resulted in a denser microstructure, which in turn enhanced the strengths and limited the autogenous shrinkage.

Effects of Using Palm Kernel Shell and Spikelet Fibers as Coarse Aggregate for Lightweight Concrete

“…3) The compressive strengths obtained for the palm kernel shell and spikelet fibre composites at 28 days curing ranged from 12.26Mpa to 25.34 Mpa, which met the compressive strength requirements with reference to previous research findings that the compressive strength of palm kernel shell composites ranges from 5 to 25 Mpa based on mix design. Kengoh et al (2021) The research also revealed that the physical and mechanical properties of palm kernel shell and spikelet fibers aggregate are satisfactory for the production of structural composites. Ezeudu et al…”

“…The specimen dimension was taken before the testing. ACI (2003), Kengoh et al (2021) The testing was carried out for 7 days, and 28 days specimen after curing…”

Extraction and characterization of a novel tropical fibre Megaphrynium macrostachyum as a biosourced reinforcement for gypsum-based biocomposites

“…Demineralised water was then added and the three components were mixed for approximately 6 min. 28 The fibrous paste was then immediately poured into a 160 mm × 40 mm × 12 mm silicone mould and lightly stirred to distribute the mixture evenly. After 15 min of drying, the samples were removed from the mould and left in the open air (temperature 25 ± 2°C and relative humidity 55%) until the mass stabilised (total drying time equal to 6 days).…”

“…Ebanda and Atangana 27 conducted research on the thermal conductivity and diffusivity of hardened gypsum, woven, unidirectional and random reinforcement of Rheckthophyllum camerunense tropical fibre bundles as a potential substitute for sisal and glass fibres. Kengoh et al 28 showed that Urena lobata fibre bundles can be used to improve the flexural strength of plaster. Betené 29 showed that fibre bundles of Rheckthophyllum camerunense and Ananas comosus can be added to plaster to improve its toughness and flexural strength, and to limit its cracking on indentation.…”

Thermal and mechanical evaluation of natural fibers reinforced gypsum plaster composite

“…It has low tensile strength and brittleness, as well as being low cost, easy shaping and lightness make gypsum favorable. Plasterboard walls and ceilings are widely used in buildings due to their many superior properties [1][2][3]. However, the use of such internal structural elements is limited in cases of damage, fire and insulation.…”