This research examines the shear strength of Sisal Fibre Reinforced Concrete (SSFRC).Sisal Fibre (SSF) addition was at 1% by weight of dry constituents, this is considered the upper limit for workable mixes in the absence of water reducing agents. Beams of various grades of concrete (20N/mm 2 to 40N/mm 2 ) were tested and they all failed in shear. Experimental results of beams were compared with modified versions of the BS 8110 formula for shear strength in concrete, to determine the best fit. The inclusion of SSF at 1% addition increased the compressive strength of the concrete mix by an average of 16.9% and the shear strength by 16%. However, the shear strengths of the SFRC are only greater than those of normal concrete of corresponding compressive strengths by 9.5%. The equation proposed may be used to estimate the shear strength of SSF reinforced concrete at this level of fibre addition.

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This study investigated effect of combined heat treatment on the hardness and tensile strength of 0.25 -0.35 grade of medium carbon steel. Heat treatment at 900 °C for four hours was done and six specimens of each were then quenched in water. Results showed that the hardness and tensile strength ranged from 113.7 to 184.4 HB and from 383.84 to 621.2 N/mm 2 , respectively, for hardening temperature from 700 to 950 °C; and were from 180.2 to 125.5 HB and 594.7 to 4143 N/mm 2 , respectively, when the steel was quenched from 900 °C for tempering temperatures from 250 to 600 °C. The result of tempering (from 250 to 600 °C) when previously quenched (from 850 °C) steel showed decreasing values of hardness (from 400 to 248 HB) and of tensile strength (from 1320 to 819 N/mm 2 ). The microstructure of the normalized sample was observed to be finer and more homogenized than the one observed in the as-rolled condition of the sample. This invariably led to the higher hardness and tensile strength values recorded.

Combining two or more polymers as a blend is necessary rather than synthesizing new ones for the balance of polymer properties for end-use applications. This work introduces a sustainable polymer blend (matrix) for high-impact applications, as the accessibility and cost of production of these high-impact polymers keep souring. This was achieved by designing an experiment using design expert v10.0 to account for the number of experimental runs and optimise the polymer blend. Mechanical, dynamic mechanical, and temperature effects were considered on the blended polymer. Sixteen (16) experimental runs were generated with blend ratio as the independent variable and Impact Strength (IS) and Tensile Strength (TS) as the responses. The optimal blend ratio was obtained for wPP, PP and NR as 23, 30 and 47 % respectively. While, the optimum conditions for maximum impact and tensile strengths from the D.E was 241.62 J/m and 118.04 MPa respectively, with a desirability of 0.973. While the validated values obtained were 248.9 J/m; with errors of 2.93 % and 120.14 MPa; with an error of 1.75 % respectively. Thermogravimetry analysis revealed a single peak degradation for sp17, sp18, and sp19 (control samples) while multiple degradation peaks were observed for the blends. It was believed to be a result of different times for degradation of the individual components forming the polymer blend. Also, the Td onset started around 300 oC and the Td offset was around 500 oC for all tested samples. While, the Dynamic Mechanical Analysis (DMA) showed that there was an improvement in the Tg and damping factor for sp5 (109 oC, 0.171) as compared to sp17 and sp18 (81.1 oC, 0.089 and 104.3 oC, 0.061), but no improvement was recorded for storage and loss moduli. SEM micrographs showed a good surface morphology for the blend with optimal mechanical and thermal properties. The blend can be utilized for engineering applications, including matrices for body armour, helmets, car bumper, etc.

In this work, the effect of jute nanofibre on ter-blend of waste polypropylene (wPP), polystyrene (PS), and natural rubber (NR) nanocomposite was studied. The nanofibre was produced from jute fibre via a ball milling process after freezing with liquid nitrogen. The produced nanofibre was analyzed using Fourier Transform Infrared Spectroscopy (FTIR) and Dynamic Light Scattering (DLS). The ter-blend was modified with the nanofibre at different weight percentages (2–10 wt%) at 2wt% intervals. The modified polymer blends were characterized for mechanical, thermal, physical and morphological properties. FTIR revealed the removal of hemicellulose, lignin and other impurities from the jute fibre, due to the change in wave numbers observed. The DLS analysis showed that an average of 85.54 nm size distribution by the intensity and Polydispersity Index (PDI) of 0.353 was achieved. Also, the thermogravimetry analysis (TGA) showed that jute nanofibres proved to be thermally stable up to 282 oC. Polymer blends modified with 2 wt% nanofibres had the highest average impact and tensile strengths. While, the percentage water absorption (%WA), showed that sp10% absorbed the highest amount of water after 24 hrs. The weight losses of the modified blend at various temperatures were found to increase with the addition of nanofibre. The Scanning electron microscope (SEM) revealed cracks, voids and blend-separation as the amount of jute nanofibre was increased. While, Dynamic Mechanical Analysis (DMA) revealed that the Tg of the modified blend was improved, while the loss-factor improved greatly by 43%, but the storage and loss-moduli remained unchanged.