Effect of Elevated Temperature on Compressive Strength and Physical Properties of Neem Seed Husk Ash Concrete

Abstract

High temperature rise mostly caused by a fire outbreak is currently becoming a threat that endangers concrete's structural performance for buildings and the safety of occupants. The behavior of concrete after fire subjection has been of much interest for the structural materials design purposes. This study investigated the physical properties and the compressive strength of M25 concrete incorporating Neem Seed Husk Ash (NSHA), exposed to and through targeted different levels of temperature (200 • C to 800 • C) for a period of three hours in an electric furnace. The NSHA was produced by calcining neem seed husks at 800 • C for six hours and then sieved through the 125 µm sieve. Different amounts of NSHA were investigated while considering the plain concrete as the control sample. 150 concrete cubes of 150 mm sizes were cast and properly cured for 7 and 28 days. The experimental results show that the compressive strength of the 5% NSHA concrete exposed to temperatures up to 400 • C is 21.3% and 23.8% better than the normal concrete at 7 and 28 curing days, respectively. Surface cracks and spalling are noticeable at 600 • C and 800 • C for all samples considered in this study.

Engineering and Durability Properties of Modified Coconut Shell Concrete

“…In addition, at 500°C for 3 hours, concrete with 10% CSA and 5% CSP increased by 5.02% compared to control. The results obtained are comparable with [68,69]. The increased strength is most likely due to the pozzolanic influence during the hydration process, which results in a huge number of C-S-H, which is responsible for strength growth [68].…”

“…The results obtained are comparable with [68,69]. The increased strength is most likely due to the pozzolanic influence during the hydration process, which results in a huge number of C-S-H, which is responsible for strength growth [68]. More so, CSA functions as a micro filler, strengthening the system's microstructure [58].…”

“…5 compares the compressive strength results obtained in this study for concrete containing 10% CSA and 5% CSP to those obtained in earlier investigations. The proposed methodology indicates a 66.08%, and 80.37% less reduction in the compressive strength at 500 °C for 1hr compared to the use of neem seed husk ash and fly ash in concrete [68,69], respectively. Incorporating a small quantity (5%) of untreated CSP in CSA concrete can still significantly enhance concrete durability.…”

“…The change of color in both concrete became more noticeable at 500°C for 2 and 3 hours, particularly the modified concrete when the time was increased. The deterioration behavior is linked to the generated pore pressures and crack growth, influenced by the heating rate and the heterogeneous concrete's composition [68]. The early color change of modified concrete can be attributed to the burning of coconut shells in concrete.…”

Influence of Sunflower Seed Husks Ash on the Structure Formation and Properties of Cement Concrete

“…In Lertwattanaruk & Makul (2021) [30] study, the introduction of rice husk ash and bagasse ash substituting a portion of cement allowed to get self-compacting concrete mixtures with optimal rheological characteristics and acceptable strength characteristics. The effectiveness of using such complex additives from several types of ash has also been confirmed by research [31][32][33][34].…”