Use of Tefla as Partial Replacement of Cement in Concrete Mix
Keywords:Porosity, Water absorption, Split tensile strength, Compressive strength, Tefla
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.
R. Mehta, "Concrete technology for sustainable development-an overview of essential principles," 1998.
Karen L. Scrivener, "Options for the future of cement," vol. 88, no. 7, pp. 11-21, 2014.
ASTM C150-17 "Standard specification for Portland cement," West Conshohocken, PA, USA., (2017).
ASTM D4318-98 "Standard test methods for liquid limit ,plastic limit ,and plasticity index of of soils " International, West Conshohocken.
ASTM D2487-98 "Standard practice for classification of soils for engineering purposes (Unifled Soil Classification System)," International, West Conshohocken.
ASTM C33-16 "Standard Specification for Concrete Aggregates," International, West Conshohocken.
ASTM C127-15 "Standard Test Method for Relative Density (Specific Gravity) and Absorption of Coarse Aggregate," International, West Conshohocken.
ASTM C131-14 "Standard Test Method for Resistance to Degradation of Small-Size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine,".
ASTM C29-17 "Standard Test Method for Bulk Density (“Unit Weight”) and Voids in Aggregate," International, West Conshohocken.
ASTM C70 "Standard Test Method for Surface Moisture in Fine Aggregate," International, West Conshohocken.
ASTM C128-15 "Standard Test Method for Relative Density (Specific Gravity) and Absorption of Fine Aggregate," International, West Conshohocken.
ASTM C1602-12 "Standard Specification for Mixing Water Used in the Production of Hydraulic Cement Concrete," International, West Conshohocken.
A. M. Neville, "Properties of concrete. Longman London,," 1995.
ACI 211.1-91 "“Standard practice for selecting proportions for normal, heavyweight and mass concrete,” ", American Concrete Institute, Famington Hills, Mich, USA.
ASTM C143-15 "Standard Test Method for Slump of Hydraulic-Cement Concrete," International, West Conshohocken.
ASTM C39-12 "Standard test method for compressive strength of cylindrical concrete specimens," ed, 2012.
ASTM C496-11 "Standard test method for splitting tensile strength of cylindrical concrete specimens," ed, 2011.
ASTM C642-13 West Conshohocken, "Standard test method for density, absorption, and voids in hardened concrete," 2013.
BS EN 12390-8 "Testing hardened concrete, Part 8: depth of penetration of water under pressure," ed: AENOR Spain, 2009.
Valenta. O. "“The Permeability of Concrete in Aggressive Condition,”in Proceedings of the 10th International Congress on Large," pp. 103–117.