Use of Tefla as Partial Replacement of Cement in Concrete Mix

Abstract

Abundant is tefla (Yellow Tefla, Green Tefla) in OmAlrozam, a town near the city of Derna, Libya. Cement is one of the components of concrete plays a great role in the construction industry. Higher consumption of cement in the construction industry leads to higher pollution. To make economic aspects in the construction industry and protecting the environment from pollution and also cement production emits CO₂ into the atmosphere which is harmful to nature. If we can partially replace the cement with the material with desirable properties then we can save natural material and reduce the emission of CO₂ into the atmosphere. This study aimed to investigate the suitability of using tefla in concrete. The tefla were ground to roughly cement fineness, which has been sieved and passing through 90 microns and after grinding, the chemical composition of the tefla material was determined using X-Ray Fluorescence (XRF). Four replacement levels,5%,10%,15% and 20% with a w/c ratio of 0.50. The workabilities of the fresh concrete mixes were evaluated using the slump test while compressive and splitting tensile strengths of hardened concrete were evaluated at different curing periods of 3, 7, 14 and 28 days, the workability of the concrete reduce with an increase in tefla powder content. Better result in mechanical properties (compressive strength and splitting tensile strength) and physical properties (water absorption and porosity) of the concrete was achieved at 5% cement replacement of yellow tefla, after which a decrease in strength with increasing tefla content was recorded. The use of yellow tefla of not more than 5% was recommended for concrete production.