Optimization of mechanical properties of cellular lightweight concrete with alkali treated banana fiber

Abstract

Recent advancements in construction materials development have involved the utilization of plant-based natural fibers such as kenaf, sisal, coir and banana to replace conventional fibers such as carbon, steel, polypropylene and aramid. However, the main issue with using these fibers is the alkaline cement matrix's durability and compatibility due to high water absorption. Hence, this research focuses on the use of alkali treatment of banana fibers to enhance the mechanical properties of cellular lightweight concrete (CLC). Banana fibers were subjected to 2%, 4%, 6%, 8%, and 10% NaOH treatment before being included in 1200 kg/m3 density CLC. Plain CLC and untreated fiber composites (0% NaOH treatment) were used as the control. Results from the study indicate that compared to the untreated fibre composites and plain control CLC at 28 days, compressive, flexural and splitting tensile strengths increased simultaneously with 6% NaOH fibre treatment to peaks of 40.6% and 59.8%, 63.8% and 117.4%, and 77.4% and 157.8% respectively. The 6% NaOH treatment of BF tremendously improved the mechanical characteristics of single fibers and BFRCLC composites. It is therefore concluded that 6% NaOH treatment of banana fibre was the optimum percentage alkali treatment for use in CLC.

Enhancing mechanical properties of mortar with short and thin banana fibers: A sustainable alternative to synthetic fibers

“…Cellulose is the primary constituent of BF, which predominantly influences its mechanical properties [ 50 ]. BF is biodegradable, cost-effective, easily extracted, and eco-friendly as it emits oxygen (O 2 ) rather than carbon dioxide (CO 2 ) [ 51 , 52 ]. It is also lightweight, possesses low density, and exhibits resistance to water and fire [ 53 ].…”

“…BF can be manually or mechanically extracted from banana stalks [ 55 ]. They are used in the form of reinforcement bars [ 56 ] or as discrete fibers [ 46 , 48 , 52 , 55 , [57] , [58] , [59] , [60] , [61] ] in mortar/concrete. It has been reported that BF has a drawback related to weaker interfacial bond strength between the fiber and the matrix [ 62 ].…”

“…It has been reported that BF has a drawback related to weaker interfacial bond strength between the fiber and the matrix [ 62 ]. To address this issue, most researchers have treated BF with alkali to enhance its surface toughness and reduce its hydrophilic nature [ 46 , 52 , 56 , 57 , 61 , 62 ]. Nensok et al [ 52 ] observed a decrease in BF diameter by 18.2 % and an increase in density by 7.4 % after treatment with a 6 % NaOH solution.…”

“…To address this issue, most researchers have treated BF with alkali to enhance its surface toughness and reduce its hydrophilic nature [ 46 , 52 , 56 , 57 , 61 , 62 ]. Nensok et al [ 52 ] observed a decrease in BF diameter by 18.2 % and an increase in density by 7.4 % after treatment with a 6 % NaOH solution. They also reported an increase in single fiber flexural strength from 166 MPa to 487 MPa and a modulus of elasticity increase from 14.3 GPa to 28.7 GPa.…”

“…Nensok et al [ 52 ] compared the mechanical properties of mortar using 0.4 % (by weight of mortar) of 30 mm BF treated with different NaOH solution concentrations. They found that using BF treated with a 6 % NaOH solution resulted in the highest compressive, flexural, and splitting tensile strengths of the mortar.…”