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Coconut husk is generated yearly as waste in large quantities but majorly under-utilized. Also, as a result of high embodied carbon, cement production is one of the largest contributors to construction sector carbon footprint. Since accumulation of unmanaged agro-waste like coconut husk has an increased environmental concern due to its pollution effect, recycling it into sustainable construction materials is a viable solution for future generation. In this study, experiments were performed to investigate the influence of coconut husk ash nanomaterial (CHAN) inclusion on electrical characteristics of plain cement paste (BCP) and mortar (CSM) samples at curing ages of 7 and 28 days. The results showed increase in electrical resistivity, thermal constant, and activation energy with curing duration for heating and cooling cycles of BCP and CSM. With inclusion of CHAN, the developed cement paste (CAP) and mortar (CASM) possessed lower values in all cases compared to their counterparts. Also, during heating at 28 days, both the CAP and CASM exhibited decrease in thermal constant. Though electrical resistance of all the samples varied inversely with temperature, CAP and CASM were found to possess greater potentials to make building structures intrinsically smart. Hence, in addition to solving disposal problems, utilization of coconut husks as described herein could enhance development of safe, inexpensive, and sustainable buildings that have large temperature sensing volume.

Periwinkle shells and cassava effluent are wastes generated in very large quantities and majorly under-utilized. Due to existence of inefficient waste management systems in developing countries, their disposal is by indiscriminate dumping, a practice that adversely affects the environment and human health. Hence, there is an urgent need to examine their potentials for possible engineering applications in order to further proffer a safe way of managing them. In this work, Periwinkle shell nanopowder and cassava starch were prepared from the wastes and then used to fabricate disc-shaped samples. The samples were developed with various lengths/thicknesses and in triplicates, after which their electrical and dielectric properties were evaluated. For lengths/thicknesses of 2.6 mm to 6.5 mm, the mean electrical resistance and electrical resistivity obtained were (9.89 to 23.00) × 106 Ω and (8.231 × 105) Ωm respectively. Over the temperature range of 20°C to 50°C, the respective results for thermal sensitivity, activation energy, and temperature coefficient of resistance assessment were (6982 ± 158) K, 0.60 eV, and −8.12 %/K. More so, it was observed that quality factor increased with sample’s thickness and frequency of applied signal. With increase in frequency from 0.10 kHz to 100.00 kHz, the dielectric constant of the studied sample decayed exponentially from (20.54 ± 0.04) to (1.67 ± 0.01). Aside meeting the market requirements for NTC thermistors, it was found that the sample could serve as a suitable alternative to conventional dielectrics like mica, paper, plastic film, tantalum oxide, and aluminium oxide for production of capacitors.

Large quantities of coconut husks generated are under-utilized. In developing countries, this situation warrants their disposal by open burning or indiscriminate dumping. Either practice adversely affects the environment and public health. In this study, test samples were fabricated from untreated coconut husk particles (UCP) at 0%, 25%, 50%, 75%, and 100% weight proportions with treated coconut husk particles (TCP) using epoxy resin as binder. Five representative samples were prepared per formulation and then subjected to various intended tests. The test results revealed water absorption, bulk density, thermal conductivity, specific heat capacity, thermal diffusivity, nailability, flexural strength, and compressive strength to be (24.88 ± 0.04) %, (459.78 ± 0.05) kgm-3, (0.0867 ± 0.0001) Wm-1K-1, (1573.76 ± 1.14) Jkg-1K-1, (1.198 ± 0.002) x 10-7 m2s-1, (100.0 ± 0.0) %, (11.94 ± 0.03) N/mm2, and (22.86 ± 0.04) N/mm2 respectively for the control sample with UCP content. Also, the respective values of the properties were (29.05 ± 0.06) %, (583.87 ± 0.05) kgm-3, (0.1009 ± 0.0002) Wm-1K-1, (1402.66 ± 1.45) Jkg-1K-1, (1.232 ± 0.004) x 10-7 m2s-1, (100.0 ± 0.0) %, (14.58 ± 0.03) N/mm2, and (33.27 ± 0.02) N/mm2 for the counterpart sample containing the TCP. All the samples showed better tendencies for thermal insulation performance compared to conventional ceilings like plywood, PVC, and asbestos. Thus, utilization of coconut husks as described in this study could alternatively help to solve the disposal problems of such wastes while availing building industries with suitable raw materials to manufacture cost-effective heat-insulating ceilings.