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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.

This paper investigates the performance of plain cement concrete (PCC) and fiber reinforced concrete (FRC) with silica fume (SF) and ultra-fine TiO2 (UFTiO2) as mineral admixtures. The size of UFTiO2 was analyzed using Zeta size analyzer. Concrete with a characteristic compressive strength of 50 MPa was chosen. Cement was partially replaced with SF in three different percentages namely 4.5, 9.5 and 14.5 and constant UFTiO2 percentage of 0.5 to have a total replacement level of 5%, 10%and 15%. Steel fibres were added in 0.5% by volume of concrete. Specimens were for various parameters like resistance against compression, water absorption and sorption. In addition, tests on Split tension, flexure and impact were done to study the characteristics of the concrete with fibre. The results were compared with conventional concrete. Concrete with 9.5% SF, 0.5% UFTiO2 was found to be an optimum mix among all the combinations tested in both plain cement and fibre reinforced concrete.

Self compacting concrete (SCC) has an ideal fluid character at the fresh state and becomes solid once it sets/hardens completely when poured on the desired shape of the mould. The increase of workability and the control of segregation were taken care by super plasticizer (SP) and viscosity modifying agent (VMA) dosages. In this paper an attempt was made to study the flexural behaviour of ternary SCC beams. Cement was replaced with two different combinations viz metakaolin (mk) + ground granulated blast furnace slag (ggbs) and silica fume + ggbs. The experimental results of these ternary beams were compared with Conventional Vibrated Concrete (CVC) & SCC control concrete (SCC 0). Fresh properties of SCC like slump flow, spread were studied in accordance with EFNARC guidelines. Flexural strength of concrete was tested at the age of 28 days. Load-deflection characteristics were studied at mid span of the beam (L/2). From the results it was observed that SCC ternary blended beams have higher flexural strength and better ductile performance compared to CVC and SCC0 beams.

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.

High performance concrete (HPC) in three different forms were used in the present research and they were made with mineral admixtures, air entraining agent (AEA) and light weight aggregate (LWA). This paper deals with compressive strength, sorptivity, porosity, corrosion resistance and load carrying capacity of HPC. Experimental results reveal that, HPC with ground granulated blast furnace slag (GGBFS) (20%) and Quartz powder (10%) gave 68.4 MPa (for fck = 70 MPa) the maximum compressive strength among three different forms used. In terms of durability the same mix showed a reduction of 60% in voids compared to control concrete. The load carrying capacity of that mix was only 6% less than control concrete. Performance of HPC made with LWA and AEA was inferior to HPC with mineral admixture. Hence HPC with GGBFS (20%) and Quartz powder (10%) was an optimum mix among the various mixes used.

The behavior of SiO2 and metakaolin in aggressive environment when used separately as a supplementary cementitious material was studied for three different replacement levels: 5%, 10% and 15%. SiO2 and metakaolin were used in two states namely unground and ground (ultra-fine). Ultra-fine state was achieved by subjecting the mineral admixtures to grinding in a planetary ball mill for an optimum period of one hour. The microstructure of the unground and ground mineral admixtures was studied using Scanning Electron Microscope and X-Ray Diffraction. The compressive strength of these systems in normal and aggressive environment was tested after initial curing in water for a month and subsequent curing in acid or base environment for a period of three months to arrive the rate of deterioration. The rate of corrosion in rebars was also determined using Half-cell potential method. The results obtained from the tests were compared with control concrete. From the results it was understood that concrete with 10% ground SiO2 and 5% ground metakaolin provided better resistance to deterioration and corrosion. It also exhibited improved microstructure as well as filler action. Comparing the results of two admixtures, performance of concrete with ground metakaolin found to be better than ground SiO2

This paper summarizes the study on effect of ceramic waste powder as partial substitute to cement in binary blend and along with silica fume in ternary blend high strength concrete in normal and aggressive environments. Strength parameters such as compression & tension and durability indices such as corrosion measurement, deterioration, water absorption and porosity were studied. Ceramic waste powder was used in three different percentages namely 5, 10 and 15 with constant percentage of silica fume (1%) as substitutes to cement in ternary blend high strength concrete was investigated. After a detailed investigation, it was understood that concrete with 15% ceramic waste powder registered maximum performance. Increase of ceramic waste powder offered better resistance to deterioration of concrete.

The exposure of alumino silicate materials such as fly ash, ground granulated blast furnace slag will undergo thermal activation along with alkaline environment and forms an environment friendly material called geopolymer. These materials not only reduce emission of carbon dioxide gas in the atmosphere but also act as a substitute for cement to meet with the future demand. In the present work a sincere attempt was made to produce ground granulated blast furnace slag (GGBFS) based geopolymer concrete (GPC) and to assess its performance by conducting parametric study such as magnitude of temperature, Alkaline liquid (AL) to GGBFS ratio, SiO3 to OH ratio and age of concrete on compressive strength. All the experiments were conducted with a constant sodium hydroxide (NaOH) molarity of 14. Detailed experimental investigations were carried out to assess the effect of the above mentioned parameters under thermal curing with three different curing temperatures of 60, 80 and 100 °C. From the experimental results it was understood that geopolymer concrete with AL/GGBFS = 0.30, SiO3/OH = 1.5 and curing temperature of 80 °C, yielded better compressive strength when compared to all the other combinations used in the present work. Hence use of GGBFS based geopolymer concrete could be feasible for any engineering construction and most preferred for precast construction.

Ground granulated blast furnace slag (GGBFS) in the present research work was commercially available ultra fine slag of size 5 μm meter was used which fills micro voids. This paper deals with compressive strength, porosity and sorptivity characteristics of commercially available ultra fine slag based high strength concrete (HSC) (with a characteristic compressive strength of 50 MPa). The results were compared with similar characteristics of precursor slag and ultra fine slag obtained by grinding (Sharmila and Dhinakaran, 2015). Ultra fine slag replaces cement with three different percentages viz 5, 10, and 15% to study the compressive strength, porosity and sorptivity. Performance of commercially available ultra fine slag was found to be inferior than ground one and concrete with 10% ultra fine slag was found to be optimum.

Steel industries produces ground granulated blast furnace slag (GGBFS) as a waste material and has enormous scope to be made use of in concrete as partial substitute to cement. The average particle size of GGBFS used was 17.5 µm. It fills voids and modifies the microstructure in turn enhancing the strength and durability of concrete. In the present work commercially available ultra fine slag (readymade ultrafine slag - RUFS) with an average size of 5 µm was used as mineral admixture in three different percentages of 30, 40 and 50 as substitute to cement. Results of present work were compared to precursor slag of author’s earlier works. From the experimental results it was understood that RUFS with 40% substitution to cement gave better performance among three different percentages used. Comparing with author’s earlier works, RUFS performed better than precursor slag and had slightly higher results than that of concrete with 5 to 15% of RUFS. Hence it is suggested that cement could be replaced with readymade ultrafine in high volume as much of 40% without compromising its performance.

The use of ground granulated blast furnace slag (GGBFS) from steel industries waste is showing perspective application in civil engineering as partial substitute to cement. Use of such waste conserves natural resources and minimizes the space required for landfill. The GGBFS used in the present work is of ultra fine size and hence serves as micro filler. In this paper strength and durability characteristics of ultra fine slag based high strength concrete (HSC) (with a characteristic compressive strength of 50 MPa) were studied. Cement was replaced with ultra fine slag in different percentages of 5, 10, and 15% to study the compressive strength, porosity, resistances against sulfate attack, sorptivity and chloride ion penetration. The experiments to study compressive strength were conducted for different ages of concrete such as 7, 28, 56, and 90 days. From the detailed investigations with 16 mix combinations, 10% ultra fine slag give better results in terms of strength and durability characteristics.

Development of sustainable concrete has now become a mandatory requirement today due to environmental problems posed by the production of conventional concrete. Many researchers focused their research toward finding alternate materials for cement, sand, steel, etc., and came out with good results. This paper focuses on feasibility of developing sustainable concrete using bamboo as infill, stiffener, and combination of infill and reinforcement in the wall panels. In addition, low-density polyethylene waste also tried as infill material with bamboo as diagonal member. The structural property of bamboo was studied for replacing the conventional steel by designing the wall panels with lower stiffness and weight to avoid the catastrophic effect. The strength and behavior of infill wall panels for different infill cases were studied under uniaxial in-plane loading. Parameters such as maximum load carrying capacity, load–deflection characteristics, and cost effectiveness of bamboo-based wall panel system were considered in the present study. From the experimental results, it was understood that bamboo-based wall panel behaved as a ductile member and failed after due to the formation of micro-cracks. Wall panel specimens were failed with an out-plan buckling and resisted the force such that the sudden collapse was avoided. It was concluded that an infill wall reduced lateral and vertical deflection, thereby decreasing the probability of collapse. Hence, an infill wall panel could be used as a substitute for conventional wall panel.

Production of high strength concrete with waste utilization attracted more attention of many researchers due to number of benefits in the present scenario. This paper discusses the effect of such waste utilization in strength, durability and structural behavior of high strength concrete by considerably replacing cement. Rice husk ash (RHA) (5 to 15%) and ground granulated blast furnace slag (GGBFS) (20 to 40%) were used as mineral admixtures in three different percentages. The range of replacement of cement with this dual mixture was kept 25% as minimum and 55% as maximum. Strength parameters such as compression & flexure and durability parameters such as sorptivity, porosity and freeze-thaw were studied. All the tests were conducted as per ASTM standards. Ten combinations of ternary mix were tested and among them mix with 30% GGBFS and 5% RHA exhibited better performance at par with control concrete by compromising characteristic compressive strength to an extent of 5%. It also yields better performance in terms of durability characteristics. Hence it was concluded that it could be possible to produce high strength concrete with 35% replacement of cement either with 20% of GGBFS and 15% of RHA or 30% of GGBFS and 5% of RHA.

The utilisation of recycled coarse aggregate obtained from demolished concrete has gained momentum in recent years due to its contribution towards sustainability by minimising the use of artificially produced materials and eliminating environmental problems due to dumped waste materials. The present research exploited the possibility of producing high-volume fly ash (HVFA)-based recycled aggregate (RA) high-strength concrete. It was found that 50% of desired strength could be achieved even with 50% replacement of cement with fly ash and 50% of natural aggregate (NA) with RA. An attempt was thus made to study the effects of RA and HVFA on durability characteristics. The parameters considered were resistance to chloride ion penetration, acid attack, sulfate attack and sorption. It was found that replacement of NA with RA and cement with fly ash in higher volumes showed a way of considering economy and environmental effects as criteria, given a little bit of compromise towards strength and durability criteria but still falling well within an acceptable limit.

In the current scenario, SCC is used in the variety of massconcreting applications. But SCC involves usage of more quantities of binder and fine aggregate content compared to conventionally vibrated concrete (CVC). The availability of basic constituent materials required for preparing the concrete in the entire world is facing a majorcrisis. For example, the construction industry has faced the non-availability of river sand since it is the principal ingredient that contributes the homogeneity in concrete. The experimental investigation was planned with the total of ten SCC mixes using industrial wastes namely copper slag (CS) and steel slag (SS) from 0% to 50% (with an increment of 10%) as fine aggregate replacement along with one control SCC (SCC0). The water-powder (w/p) ratio of 0.38, the dosage of Super plasticizer (SP) as 1.5% by the weight of cement and viscosity modifying agent VMA as 0.15% by the weight of cement were arrived based on the laboratory test trials. The fresh property tests were conducted in greener SCC according to EFNARC guidelines. The mechanical properties(compressive strength and split-tensile) were determined after 28 days of curing. Keywords: Compressive strength; copper slag; self-compacting concrete; splitting tensile strength; steel slag.

In the present research work, investigations were carried out to improve the performance of concrete in terms of strength and resistance to chloride-ion-penetration by incorporating metakaolin (MK) as mineral admixture in concrete. Parametric study was carried out by considering w/cm ratio, various percentage of MK and age of concrete as parameters to understand the effect of each parameter. The study was conducted for different water-to-cement metakaolin ratio (w/cm) ratios of 0.32, 0.35, 0.4 and 0.5. The MK proportion was varied from 0 to 15% with an increment of 5% and ages of concrete from 3 to 90 days were considered and experiments performed accordingly. The effects of above said parameters on the various properties of concrete such as workability, compressive strength, chloride penetrability (Rapid chloride permeability test as per ASTM C 1202), pH of concrete and depth of penetration of chloride ions were investigated, and the results of MK concrete were compared with the conventional concrete. From the results, it was observed that MK concrete showed greater strength for higher w/cm ratios (0.4 and 0.5) and its resistance to chloride ion penetration was more or less consistent for all w/cm ratios and the optimal amount of MK resulted significant reduction in chloride ion penetration. A Multiple non-linear regression analysis was used to develop a statistical model to predict the strength and found to have good correlation between the observed and predicted values. It was concluded that the concrete developed in this study have significant potential for use on real time projects.

Scientists and researchers are currently focusing considerable attention on the hydrodynamic characteristics of semicircular breakwaters worldwide, particularly in Japan and the People’s Republic of China. A semicircular breakwater is a composite breakwater made of prestressed concrete and has several merits over a conventional rubble mound breakwater, e.g. it is technically advanced, economically viable and aesthetically pleasing. At low water levels, it serves as a rubble mound breakwater and, at high water levels, it acts as a composite breakwater in the emerged condition. It reduces the considerable magnitude of dynamic forces if constructed in front of a vertical wall (the main structure) under the submerged condition and also reduces coastal erosion along the shoreline. Many research studies are being carried out all over the world to evaluate the performance of a semicircular breakwater in the laboratory and in the field. The authors of this review paper have also conducted a large number of experiments to study the hydrodynamic characteristics of a semicircular breakwater and to optimize the parameters such as the rubble mound height, the water depth and the size of perforations. The experiments were conducted for both the emerged condition and the submerged condition subjected to regular and random waves with various wave heights and periods to find the suitability of a semicircular breakwater in the field, and the optimum parameters were recommended in their previous publications. Hence, a sincere attempt has been made in this review paper to present the ongoing research on semicircular breakwaters, which has been carried out all over the world to facilitate the studies of researchers and to provide related information to people working in the area of semicircular breakwaters.

Recycled aggregate (RA) obtained from crushed concrete rubble, instead of being stored, can be reused in building industry. An attempt has been made to study the possibility of reusing the recycled concrete aggregate from demolished structures in the place of fresh aggregate. Four series of mixes of control concrete with fresh aggregate and recycled concrete aggregate with three different ages of 5, 10, and 15 years were prepared for the present study and used with three different combinations, 0% fly ash, 20% fly ash, and 20% fly ash with super plasticizer. The basic properties of aggregates, such as water absorption and specific gravity, mechanical properties, such as abrasion resistance, effect, and crushing values were considered. Workability of fresh concrete and strength parameters of hardened concrete, such as compressive strength and tensile strength, were studied. The preceding properties were tested for three different periods of curing of 7, 14, and 28 days. All these mixes were designe...

The present study investigated how the aggregate characteristics namely individual size, grade and type affects flowability of mortar mixes. Two types, river sand and crusher dust four single sizes namely 1.18 mm, 0.600 mm, 0.300 mm, 0.150 mm and for single gradation of each fine aggregate were considered in the present research work. In total, 103 mortar batches was made with three different sand to cement ratios [s/c] and two different water to cement ratios [w/c] to find out the flowability of mortar and tested using standard flow table. Out of 103 mortar batches, 52 were with river sand and 51 were with crusher dust. Tests were performed as per ASTM 109 standards. S/c ratio varied from 1 to 3 with an increment of one and w/c ratio was chosen in such a way that all the mixes to give measurable flow. The influence of particle shape and surface texture of aggregate were characterized with an angularity test based on ASTM C1252 in terms of percent of air voids in a loosely compacted fine aggregate. The results indicate that the size of aggregate and uncompacted void content have greater impact flowability of mortar. Mortar made with river sand has got better flowability than that of mortar made with crusher dust due to its higher degree of irregularities. Mortar with higher aggregate content has low percentage of spread compared to mortar with low aggregate content. Similarly, graded aggregate has lesser percentage of spread due to its proper packing compared to single sized aggregates.

The Andaman Sea is known for the genesis of many severe cyclones that traverse the Bay of Bengal. The Andaman Islands face the surge disaster threat as their north-south orientation comes across the eastward path of severe cyclones moving from the Andaman Sea and western Pacific Ocean. In this study, we investigated the potential of a storm-induced surge—a natural disaster due to short-duration sea-level rise—to affect the Andaman Islands. A two-dimensional hydrodynamic model was employed to simulate storm surge characteristics and demarcate the coastal flooding extent of the highly inhabited Port Blair region of the Andaman Islands in the case of the severe cyclone of November 1989. A storm surge disaster mitigation plan is also proposed for the group of Andaman Islands.

The semicircular breakwater (SBW) is a composite breakwater consisting of a semicircular caisson resting on a rubble mound. The SBW function as a barrier dissipates the incident wave energy and creates tranquility on its leeside. The dynamic pressures due to regular waves exerted on seaside perforated SBWs with 7 and 11% of exposed surface area with perforations were measured. The measured pressures are compared with those exerted on impermeable SBWs. In addition, the forces exerted on the caisson alone are measured. The reflection coefficient, measured total forces on the caisson of the models, and the pressures are presented as functions of relative water depth. The effect of the water depth and the percentage of perforations on the above stated variables are examined, details of which are reported in this paper. ? 2002 Elsevier Science Ltd. All rights reserved.

The conventional concrete when used for structures having dense congested reinforcement, the problems such as external compaction and vibration needs special attention. In such case, the self compacting concrete (SCC) which has the properties like flow ability, passing and filling ability would be an obvious answer. All those SCC flow behavior was governed by EFNARC specifications. In present study, the combination type of SCC was prepared by replacing cement with silica fume (SF) and metakaolin (MK) along with optimum dosages of chemical admixtures. From the fresh property test, cube compressive strength and cylinder split tensile strength, optimum ternary mix was obtained. In order to study the flexural behavior, the optimum ternary mix was taken in which beam specimens of size 1200 mm x 100 mm x 200 mm was designed as singly reinforced section according to IS: 456-2000, Limit state method. Finally the comparative experimental analysis was made between conventional RCC and SCC beams of same grade in terms of flexural strength namely yield load & ultimate load, load- deflection curve, crack size and pattern respectively.

In the majority of civil engineering applications, the basic building blocks were the masonry units. Those masonry units were developed as a monolithic structure by plastering process with the help of binding agents namely mud, lime, cement and their combinations. In recent advancements, the mortar study plays an important role in crack repairs, structural rehabilitation, retrofitting, pointing and plastering operations. The rheology of mortar includes flowable, passing and filling properties which were analogous with the behaviour of self compacting concrete. In self compacting (SC) mortar cubes, the cement was replaced by mineral admixtures namely silica fume (SF) from 5% to 20% (with an increment of 5%), metakaolin (MK) from 10% to 30% (with an increment of 10%) and ground granulated blast furnace slag (GGBS) from 25% to 75% (with an increment of 25%). The ratio between cement and fine aggregate was kept constant as 1: 2 for all normal and self compacting mortar mixes. The accelerated curing namely electric oven curing with the differential temperature of 128°C for the period of 4 hours was adopted. It was found that the compressive strength obtained from the normal and electric oven method of curing was higher for self compacting mortar cubes than normal mortar cube. The cement replacement by 15% SF, 20% MK and 25%GGBS obtained higher strength under both curing conditions.

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 submerged semicircular breakwater (SBW) is mainly adopted to prevent beach erosion and to reduce the incident wave energy on its leeside, if it is used in front of a vertical breakwater. In addition, it facilitates the premature wave breaking, which in turn causes the reduction in wave energy. The dynamic pressures and forces exerted on the submerged SBW with 7%, 11%, and 17% of the exposed surface area with perforations on its seaside due to regular waves were measured. The hydrodynamic characteristics such as variations in the dimensionless pressures and forces, reflection and transmission coefficients on the semicircular caisson as a function of scattering parameter for three different water depths are presented and an optimum depth of submergence is arrived. The results on the above stated variables for seaside perforated SBWs are compared with the results of an impermeable SBW to study the effect of perforations. Copyright � 2010 by ASME.

Operational analysis of transportation facilities is critical for making efficient use of existing transportation resources and for proposing improvements. Signalized intersections are the most complex locations in urban networks. The operational conditions of such intersections profoundly affect the well being of the transportation of goods and passengers in cities. There are several methods available for operational analysis including mathematical models and traffic simulation models; however the Highway Capacity Manual (HCM) has been widely accepted and applied as a standard method. Three Measures of Effectiveness (MOE) commonly used to evaluate signalized intersection operations are capacity and volume-tocapacity (v/c) ratio, delay and queue. In the present research work, an attempt is made to estimate the capacity and v/c ratio, control delay and assign them to a Level of Service (LOS) at three identified signalized intersections of a medium sized city in India. The results obtained are analysed and remedial measures suggested to improve the operational performance of study intersections. In addition, the field measured control delay is compared with HCM 2000 delay model and Gopal Patil (2002) delay model developed for mixed traffic in India

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.

Non–metallic reinforcement is of recent origin to eliminate the corrosion problems in concrete structures and is having very good qualities, which are required to tailor the need of anti corrosive reinforcement. Glass Fibre Reinforced Polymer (GFRP) rebars comes under this category and its structural properties makes it to use for variety of applications. Hence, an attempt is made to find the suitability of GFRP rebar as reinforcement for compression members. This paper aims to investigate the possibilities of identifying suitable alternate reinforcement to steel and compare their performance in terms of load carrying capacity. M60 grade of concrete was chosen for the study and the cross section of the compression member chosen is square. The slenderness ratios of 6 and 8 were adopted and the end conditions are pinned. A critical analysis is made with experimental investigations. It is concluded that the load carrying capacity of GFRP reinforced column is 56% and 40% more compared to steel reinforced column for slenderness ratios of 6 and 8 respectively.

The semicircular breakwater (SBW) is one of the varieties of breakwaters, which has emerged recently. The world’s first semicircular breakwater has been constructed at Miyazaki port in Japan. The dynamic pressures due to regular waves exerted on a SBW with 7% of its seaside surface area with perforations were measured. The variations of dimensionless pressures for three different water depth (hw ) to total height of the model (ht ), ratios are presented and discussed in this paper. In addition, the reflection and transmission characteristics of the perforated SBW as a function of scattering parameter, ka is reported. The results on the above stated variables for a seaside perforated SBW are compared with the results for an impermeable SBW.Copyright © 2002 by ASME