Improvement of Concrete Properties and Reinforcing Steel Inhibition Using a Natural Product Admixture

The use of a natural white juice, taken from magrabe banana stem, as concrete admixture to improve mechanical and physicrvchemical properties of concrete has been studied. The compressive strength, bulk density the free lime liberated during hydration and the combined water content were determined. The results indicate that the admixture acts as a retarder in most cases and as accelerator in some ones. Also, the admixture effect on the corrosion resistance of the reinforcing steel against surrounding aggressive media has been investigated using galvanostatic polarization technique. The addition of 0.2% admixture leads to the more inhibition of the

Evaluation the Effects of Coarse Aggregates Size on Concrete Properties

Concrete is the most generally used construction material in buildings,pavements,and infrastructures.Concrete is a construction material composed of cement as binder,fine aggregates and coarse aggregates mixed with water which hardens with time.Concrete is a versatile construction material within the housing industry of the planet.The standard of the concrete is tormented by various factors and from those various factors which may have an effect on the concrete quality are,the coarse combination size has its own nice role on the standard of concrete production.A laboratorial experiment was conducted to work out the results coarse aggregates size on recent and hardened concrete properties.For this study totally different crushed volcanic rock aggregates sizes were collected from almost Jimma city for determination of the results of coarse aggregate sizes in concrete production.Three coarse aggregate nominal sizes of 10 mm,14 mm and 20 mm were used for samples production to envision the scale effects on concrete properties.For this study the procedures that was followed,the types and quantity of materials for concrete creating were similar whereas sizes of nominal basaltic coarse aggregate were different.The fresh concrete has a slump value of 67 mm,72 mm and 83 mm for 10mm,14 mm and 20 mm aggregate sizes respectively.A total of thirty six concrete cube samples were ready and tested using compressive strength testing machine at totally different ages of the cube 7 days,14 days,and 28 days,to know their strengths.The compressive strength was 23.524 Mpa,22.643 Mpa and 22.41 MPa for aggregate sizes of 10 mm,14 mm and 20 mm respectively.The laboratory results show that 10mm coarse aggregate size gave the most effective compressive strength and comparatively lowest slump at similar water/cement ratio of 0.6.At 28th day 10mm coarse aggregate size gave 23.524 Mpa compressive strength which is the maximum compressive strength from the remainder coarse aggregates so,the optimum maximum size of coarse aggregate for this study was 10mm.

Modified Concrete Using Polyethylene Terephthalate Plastic Waste as a Partial Replacement for Coarse Aggregate

The present work evaluated the properties of modified concrete using polyethylene terephthalate (PET) bottle waste as a partial replacement for coarse aggregate. Modified concrete samples were designed using a water/cement (W/C) ratio of 0.50 and varying percentages of PET replacement (3%, 7%, 10%, and 15% by volume). Dreux Gorisse’s formulation approach was used to make the final products, and the mechanical properties of the samples were determined using Controlab presses. This modified concrete with PET chips has shown that with a 10% replacement of PET chips, the fresh density decreases by 3.56%, and the hardened state density decreases by 2.01%. The water absorption and thermal conductivity of the formulated concretes decreased. However, the results showed that the slump of these fresh concretes increased as the percentage of plastic aggregate replacement increased. Based on the results, incorporating PET aggregates into concrete contributes to good workability, and lightweight concrete structures, and provides some thermal comfort in concrete structures.

Perspective of E-Waste in Concrete: A Review

In this digital era,usage of electric and electronic devices has become the need of people.Evolution of technology triggers the adoption of new devices over old and discarded appliances turned into the electronic wastes also termed as e-waste/s.E-waste from any source has become a major concern to the society.The disposal of these wastes into the landfills causes many hazardous impacts to the ecosystem.As a promising solution construction industry can utilize the e-wastes effectively.The wastes may be used either as fine filler or aggregates in concrete and bituminous based constructions efficiently.Usage of waste/s conserves the natural resources also.Present study magnifies the scenario of application of electronic wastes in different forms i.e.,plastic,metal etc.in bituminous and concrete based mixtures.A critical review has been carried the effects of electronic wastes in concrete and bituminous mixes and findings confirm the praxis of electronic wastes is possible within certain limits.