Abstract:
Some construction materials are susceptible to termites attack, Termites’ entrance in to the building or other construction materials is mostly through the walls made of sandcrete blocks. In an attempt to effectively protect these construction materials from termite attack, it is more effective to deal with pathway through which termites gain access to them. The toxicity of available synthetic chemicals to human health and the environment calls for the use of alternative natural plants as insecticides and developed them as termite-repellent materials which have no effect on the environment and people. One of such plants identified is Jimson weed (Datura stramonium) used in this research work. Metal analysis was carried out on both its seeds and leaves, the seed were identified to be more acidic and repelled termites. The seed was grinded, the aqueous seed extract with a concentration of 0.2 mg/l was subjected to phytochemical analysis (dissolved oxygen, hardness, alkalinity, nitrate, pH and chlorides), phytochemical analysis results were compared with the Nigeria Industrial Standard (NIS) values for compliance. The aqueous seed extract with 0.2 mg/l concentration was added to tap water ranging from 0 % (as control), 5 %, 10 %, 15 % and 20 % by volume of water needed to mould block. A mix ratio of 1:6 at 0.8 water/cement ratio were adopted. Sixty (60) numbers 150 X 225 X 450mm sandcrete blocks were made and subjected to crushing by compressive machine to determine their compressive strength after curing for 7, 14, 21 and 28 days respectively to know which of the extract solution gave the highest compressive strength and complies with construction standards. Water absorbtion test was carried out to determine the water absorbtion rate. The results showed that Datura stramonium extract is found to be acidic, making it very toxic to termites attack. The compressive strength of sandcrete hollow block made from D. stramonium extract increases with increasing curing time. The hollow sandcrete blocks made at 20 % dilution percentage and cured 28 days had compressive strength of 3.54 N/mm2 which is above the minimum compressive strength of 3.4 N/mm2 after curing for 28days stipulated by Nigerian Industrial Standard NIS (2004). Water absorbtion results showed a range 4.5% and 9.2% which complies with less than 12% stipulated by Nigerian Industrial Standard NIS (2004). It is hereby suggested that Datura stramonium extract should be introduced in manufacturing construction materials for Engineering industry. This study provide baseline information in scientific knowledge and research in developing bio-based preservatives from plants.
