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The optimal design of reinforced concrete beams (RCBs) and structures with an objective of improving the chosen performances is an important problem in the field of construction works. Recently, the concrete beams, structures, and walls are strengthened externally by bonding fiber-reinforced polymer strips (FRPS). Usually, FRPS are employed in rehabilitation of existing beams, bridges, and other structural elements. This article modifies the problem of designing new RCBs with appropriate selection of FRPS with a goal of exploiting the benefits of FRPS such as higher tensile strength, better corrosion resistance, higher stiffness-to-weight ratio, and longer life. It, firstly, proposes an artificial neural network-based mathematical model for assessing the performances of RCBs bonded with FRPS from the data obtained from 69 FRPS-glued RCBs and then develops an optimal design procedure employing flower pollination-based optimization, which is imitated from the pollination process of plants, for obtaining design parameters of FRPS-glued RCBs with a view of enhancing both the ultimate load and the deflection ductility. It presents optimal design parameters of five FRPS-glued RCBs and experimentally validates the performances.

Self compacting concrete (SCC) made a remarkable impact on the concrete construction industry because of its innovative nature. Assessment of optimal ratio between chemical and mineral admixtures plays a vital role in developing SCC. In the present work three different mineral admixtures were used as partial substitute in different proportions to cement to produce SCC with a characteristic compressive strength of 60 MPa. All the three types of SCC were investigated for its fresh and hardened properties. From the results, 50% GGBFS, 10% SF and 20% MK were found to the optimum values as partial substitute to cement.

The present experimental research work focused on how a semicircular breakwater performs hydrodynamically under submerged conditions. In the field, a submerged semicircular breakwater may be preferred in front of the vertical breakwater to mitigate the wave forces and to minimize coastal erosion on its lee side. Various parameters affect the hydrodynamic performance of a semicircular breakwater such as the reflection and transmission characteristics, the dimensionless pressures, the horizontal forces and the vertical forces, and these are considered in the present study. Experiments were performed for three different perforations, namely 7%, 11% and 17%, of the exposed surface area with perforations on its sea side (sea-side perforated) and on both sides (fully perforated) owing to regular and random waves. The effect of the water depth was also studied in addition to the effect of perforation. All the hydrodynamic characteristics considered for the present study on the semicircular caisson are presented as functions of the relative water depth, and optimal conditions were determined. The results on the above-stated variables for sea-side-perforated semicircular breakwaters and fully perforated semicircular breakwaters are compared with the results of an impermeable semicircular breakwater. � Institution of Mechanical Engineers 2011.

Performance of glass fiber reinforced polymer (GFRP) reinforced high performance concrete compression members under axial loading were studied by conducting detailed experimental investigations. For the present study, twenty-four square columns of size 150 mm and slenderness ratios of 6, 8, 10 and 12 were cast, in which twelve columns reinforced with GFRP and the remaining twelve with conventional steel. For each slenderness ratio, three different percentages of reinforcement was tried with 1.4%, 2% and 3.5% each as longitudinal reinforcement for both GFRP and steel. Performance characteristics such as load carrying capacity, axial deformation, lateral deformation and rebar axial strain were studied in detail. Parametric study was done taking L/D ratio and percentage of reinforcement as parameters. Keywords: Load carrying capacity, axial deformation, lateral deformation, rebar axial strain, L/D ratio, Glass Fiber Reinforced Polymer

The present study investigated how the perforations, water depth and rubble mound height on fully perforated semicircular breakwater (SBW) affects non-breaking wave transformations. SBW model with surface piercing condition for three different perforation ratios with 7 percentage, 11 percentage and 17 percentage were considered to study the variation of reflection, transmission, run-up characteristics and dimensionless horizontal and vertical forces as a function of relative water depth and the results are compared with an impermeable SBW and seaside perforated SBW models. From the results it is understood that, SBW with perforation ratio 17 percentage in the case of seaside perforated case shows reverse trend in hydrodynamic characteristics and for fully perforated SBW, it transmits large amount of wave energy on the seaside, which affects the tranquillity condition in the harbour. In addition, transmission characteristics of SBW models and conventional rubble mound breakwater model are compared to understand the effect of composite breakwater action and also the reflection characteristics of SBW models are compared with field data of Miyazaki Port after Sasajima et al. (1994). The results reveal that the SBW model with perforation ratio of 11 percentage in seaside and fully perforated type gives an optimum performance in terms of energy dissipation and transmission. � 2009 Elsevier Ltd. All rights reserved.

Considerable research has focused on the effect of mineral admixtures on concrete during the past two decades. Suitable addition of mineral admixtures like fly ash (FA), silica fume (SF), metakaolin (MK) etc., in concrete improves strength and durability characteristics of concrete. This paper presents the laboratory investigation on the effects of mineral admixtures and water binder ratio on compressive strength is discussed. The study was conducted for three different mineral admixtures namely; FA, SF and Mk with different water cement ratios of 0.32, 0.35, 0.4 and 0.5. The admixture proportion varies from 0 to 15% with an increment of 5% for SF and MK and 10 to 30% with an increment of 10% for FA. The compressive strengths were determined at the age of 3, 7, 14, 28 and 90 days with and without admixture and a comparative study was also made. From the results it is concluded that FA based concrete offered more strength for lower water cement ratios (0.32 & 0.35) and MK modified concrete showed greater strength for higher water cement ratios (0.4 & 0.5). The strength enhancement of SF concrete was more or less similar for all water cement ratios. The outcome of this research work provides an optimal and economical mix for better strength.