IMPACT : International Journal of Research in Engineering & Technology

1-12

Authors: GRACEMODUPEOLAAMUSAN & FESTUSADEYEMIOLUTOGE

This research presents the effect of seawater on shrinkage properties of concrete. Concrete cubes of 150x150x150 (mm) with mix ratio 1:2:4 by weight of concrete 0.6 water-cement ratio were made in two batches. Half of the cubes (i.e. were made using fresh water and the other half were made using seawater. They were cured in fresh and sea water respectively for 90 days. Shrinkage at 90 days and ultimate shrinkage were analysed in accordance to American Concrete Institute manual on concrete and BS 8110: Part 2 respectively. Also coefficient that deals with concrete compositions such as slump, cement content, and aggregate size were varied so as to evaluate its effect on shrinkage. The findings revealed that shrinkage was interdependent on concrete composition and the result exhibited a higher shrinkage value for concrete with higher cement content and with higher slump value. However, reduced shrinkage values were noticed with higher aggregate sizes. It was also observed that concrete mixed or cured with seawater has higher shrinkage value than the control batches with dry shrinkage analysis value of 83.5% increase for concrete mixed with seawater (CSW) when compare to the shrinkage value of the control batches.

17-24

Authors: AHSANA FATHIMA K M & SHIBI VARGHESE

This paper presents the results of an experimental study investigating the effects of steel fibres and polypropylene fibres on the mechanical properties of concrete. Experimental program consisted of compressive strength test, split tensile strength test and flexural strength tests on steel fibre reinforced concrete and polypropylene fibre reinforced concrete. Three types of fibres used are hooked end steel fibre of length 30mm, crimped steel fibre of length 25mm and enduro-600 polypropylene of length 50mm with aspect ratio 50. The main aim of this experiment is to study the strength properties of steel fibre and polypropylene fibre reinforced concrete of M30 grade with 0%, 0.25%, 0.5%, and 0.75% by volume of concrete. This study consisted of compressive strength test and split tensile strength test on hybrid fibre reinforced concrete with 0.5% polypropylene fibres and 0.75% steel fibres.

39-46

Authors: AKASH AGRAWAL, NARENDRA KUMAR GARG & RAHUL SHARMA

Rectangular microstrip patch antenna is low profile, light weighted and easy to fabricate, but it also have some drawbacks like low efficiency, high return loss, low directivity etc. In this paper, metamaterial structure have been incorporated on patch antenna for improving the parameters of microstrip patch antenna. Metamaterial has few unique and unusual properties due to negative values of permittivity and permeability, with these properties; the Metamaterial will be mainly used to focus on the radiation of the patch antenna and improved parameters of patch antenna. The suggested microstrip patch antenna along with metamaterial cover provides the better response in comparison to patch antenna alone. In this work, the bandwidth of directional device has become twice and the return loss reduced more than one by two times of previous one.