International Journal of Civil and Structural Engineering 

About: International Journal of Civil and Structural Engineering is an academic journal. The journal publishes majorly in the area(s): Compressive strength & Flexural strength. Over the lifetime, 390 publications have been published receiving 2907 citations.

Effect of aggregate type on Compressive strength of concrete

Abstract: The utilisation of three types of aggregate for concrete work is investigated in this paper. Normal concrete is being produced from different types of aggregate and this imparts different property to the resulting concrete. The most important property of concrete is its compressive strength. For the purpose of this work, three types of coarse aggregates, quartzite, granite, and river gravel, were used. The fine aggregate is normal sand obtained from a borrow pit. Preliminary laboratory investigation was conducted to ascertain the suitability of using the aggregates for construction work. Tests conducted include sieve analysis, bulk density, and specific gravity. Nominal mix (1:2:4) was adopted for this work and mix compositions were calculated by absolute volume method. For each type of coarse aggregate 75 cubes (150x150mm) were cast to allow the compressive strength to be monitored at 3, 7, 14, 21, and 28 days. Test result show that concrete made from river gravel has the highest workability followed by crushed quartzite and crushed granite aggregates. Highest compressive strength at all ages was noted with concrete made from quartzite aggregate followed by river gravel and then granite aggregate. Compressive strength models were proposed as a function of age at curing. Where concrete practitioners have options, aggregate made from quartzite is advisable to be used for concrete work.

Effect of marble dust on strength and durability of Rice husk ash stabilised expansive soil

Abstract: This paper presents the results of a laboratory study undertaken to investigate the effect of Marble dusts on strength and durability of an expansive soil stabilized with optimum percentage of Rice Husk ash (RHA). The optimum percentage of RHA was found out be 10% based on Unconfined Compressive Strength (UCS) tests. Marble dust was added to RHA stabilized expansive soil up to 30%, by dry weight of the soil, at an increment of 5%. Compaction tests, UCS tests, Soaked California Bearing Ratio (CBR) tests, Swelling pressure tests and Durability tests were conducted on these samples after 7 days of curing. The UCS, and Soaked CBR of RHA-stabilized expansive soil increased up to 20% addition of Marble dust. Further addition of Marble dust had negative effects on these properties. The Maximum Dry Density(MDD) and Swelling pressure of expansive soil goes on decreasing and Optimum Moisture Content (OMC) goes on increasing irrespective of the percentage of addition of Marble dust to RHA stabilized expansive soil. From the Durability test results it was found that the addition of Marble dust had made the RHA stabilized expansive soil durable. For best stabilization effect the optimum proportion of Soil: Rice husk ash: Marble dust was found to be 70: 10: 20.

Flexural behaviour of reinforced Geopolymer concrete beams

Abstract: Efforts are urgently underway all over the world to develop environmentally friendly construction materials, which make minimum utility of fast dwindling natural resources and help to reduce greenhouse gas emissions. In this connection, Geopolymers are showing great potential and several researchers have critically examined the various aspects of their viability as binder system. Geopolymer concretes (GPCs) are new class of building materials that have emerged as an alternative to Ordinary Portland cement concrete (OPCC) and possess the potential to revolutionize the building construction industry. Considerable research has been carried out on development of Geopolymer concretes (GPCs), which involve heat curing. A few studies have been reported on the use of such GPCs for structural applications. In this paper, studies carried out on the behaviour of room temperature cured reinforced GPC flexural members are reported. A total of eighteen beams were tested in flexure. Three conventional concrete mixes and six GPC mixes of target strength ranging from 17 to 63 MPa and having varying combinations of fly ash and slag in the binder phase were considered. The reinforcement was designed considering a balanced section for the expected characteristic strength. All the specimens were tested under two-point static loading. The studies demonstrated that the load carrying capacity of most of the GPC beams was in most cases marginally more than that of the corresponding conventional OPCC beams. The deflections at different stages including service load and peak load stage were higher for GPC beams. However, the ductility factor was comparable to that of OPCC beams. The studies showed that the conventional RC theory could be used for reinforced GPCC flexural beams for the computation of moment capacity, deflection, and crack width within reasonable limits.

Influence of Marble powder/granules in Concrete mix

Abstract: In this paper the effect of using marble powder and granules as constituents of fines in mortar or concrete by partially reducing quantities of cement as well as other conventional fines has been studied in terms of the relative workability & compressive as well as flexural strengths. Partial replacement of cement and usual fine aggregates by varying percentage of marble powder and marble granules reveals that increased waste marble powder (WMP) or waste marble granule (WMG) ratio result in increased workability and compressive strengths of the mortar and concrete.

Seismic Analysis of Steel Braced Reinforced Concrete Frames

Abstract: Steel braced frame is one of the structural systems used to resist earthquake loads in multistoried buildings. Many existing reinforced concrete buildings need retrofit to overcome deficiencies to resist seismic loads. The use of steel bracing systems for strengthening or retrofitting seismically inadequate reinforced concrete frames is a viable solution for enhancing earthquake resistance. Steel bracing is economical, easy to erect, occupies less space and has flexibility to design for meeting the required strength and stiffness. In the present study, the seismic performance of reinforced concrete (RC) buildings rehabilitated using concentric steel bracing is investigated. The bracing is provided for peripheral columns. A fourstorey building is analyzed for seismic zone IV as per IS 1893: 2002 4using STAAD Pro software. The effectiveness of various types of steel bracing in rehabilitating a four storey building is examined. The effect of the distribution of the steel bracing along the height of the RC frame on the seismic performance of the rehabilitated building is studied. The performance of the building is evaluated in terms of global and story drifts. The study is extended to eight storied, twelve storied and sixteen storied building. The percentage reduction in lateral displacement is found out. It is found that the X type of steel bracing significantly contributes to the structural stiffness and reduces the maximum interstorey drift of the frames.