iosr-JMCE   Volume-17 ~ Issue-1 ~ Jan. - Feb. 2020

Abstract: Using reinforced concrete shear walls and cores is one of the most effective systems in resisting lateral loads. Analysis of buildings under the effect of lateral loads is performed using highly sophisticated commercial software finite element analysis packages. In order to account for concrete cracking, the design of these cores is performed using interaction diagrams, based on the relevant code idealization of the strain diagram throughout the section height. This idealization does not consider the torsional movement of these cores in computation of their ultimate capacity. Previous research by the authors studied the difference in behavior between regular and irregular shapes of cores, especially those which have discontinuity in web at load direction. Additionally, an extensive study was conducted to investigate the actual structural behavior of cores of different section shapes.....

Keywords : Finite Element Modeling, Reinforced Concrete cores, Nonlinear analysis, Cracked section analysis

[1]. ABAQUS Manual, ABAQUS Version 6.11.
[2]. ACI Committee, American Concrete Institute and International Organization for Standardization, 2008. Building code requirements for structural concrete (ACI 318-08) and commentary. American Concrete Institute.
[3]. CEN (ComitéEuropéen de Normalisation). 2004. Eurocode 2: Design of Concrete Structures – Part 1: General Rules and Rules for Buildings, EN 1992-1-1:2004. Brussels:CEN. 230 p.
[4]. Chaudhari, S.V. and Chakrabarti, M.A., 2012. Modeling of concrete for nonlinear analysis using finite element code ABAQUS, International Journal of Computer Apllications, Volume 44 (7), pp.14-18.
[5]. ECP 203 (2012), ―Egyptian Code of Practice for Design and Construction of Reinforced Concrete Structures 2012.‖.

Abstract: The use of silica fume as a mineral admixture to produce high strength high performance concretes is gaining importance in recent years. This paper presents better understanding of the efficiency of silica fume in concrete and experimental work on the properties of fresh and harden concrete containing different levels of silica fume. The aim of the study was to investigate the effects of binder systems containing different levels of silica fume on fresh and harden properties of concrete. The work was focused on concrete mixes having a fixed water cement ratio of 0.35 with the addition of super plasticizer at a constant total binder cement content of 412 kg/m3. The percentage of silica fume replaced with cement in this research was: 5%, 10%, 15% and 20%. At 10% replacement of cement with silica fume, it gave the highest compressive strength. But higher replacement of cement by silica fume gave lower strength.

Keywords: Compressive strength, spit tensile strength, flexural strength, Silica fume, Slump test, w/c ratio

[1]. Mohammad Iqbal Khan, Rafat Siddique, (2011) "Utilization of silica fume in concrete: Review of durability properties"; 2011
[2]. Assem A.A Hassan, Mohamed Lachemi, Khandaker M.A Hossain, (2012) "Effect of metakaolin and silica fume on the durability of self-consolidating concrete"
[3]. Erhan Guneyisi, Mehmet Gesoglu, Seda Karaoglu, Kasim Mermerdas, (2012) "Strength, permeability and shrinkage cracking of silica fume and metakaolin concretes".
[4]. Ardra Mohan, K.M. Mini,(2018) "Strength and durability studies of SCC incorporating silica fume and ultra fine GGBS"
[5]. Prof. Vishal S. Ghutke, Prof. Pranita S.Bhandari,(2014) "Influence of silica fume on concrete"

Abstract: Retempering is defined as, ''Addition of water and remixing of concrete or mortar which has lost enough workability to become unplaceable ''. Retempering in results in some loss of strength compared with the original concrete. Adding water to a plastic mix to increase slump is an extremely common practice, even though it is not recommended because it increases the porosity of concrete. Concrete often arrives on site more than half an hour after initial mixing. Placement operations can take anywhere from 10 to 60 min, depending on the field conditions and the size of the load. When the slump decreases to an unacceptable level during the operations, water is added to the mix. In this work, an attempt is made to study the strength characteristics of retempered concrete after 8 to 10 year old concrete structure by taking NDT. Durability of retempered concrete is affected after retempering time of 50 min and durability of concrete is depending up on 28 days strength of concrete.

Keyword: Compressive Strength, Retempering, Durability, destructive testing and Non destructive testing.

[1]. M.S. Shetty, "Concrete Technology Books", S. Chand and company Ltd. 1st edition 1982
[2]. A.R. Pethkar, G.Deshmukh "Retempering of Concrete made by using Manufactured Sand" J. Inst. Eng. India Ser. A (April-June 2014) 95(2):105-108
[3]. A.R. Pethkar, G.K.Deshmukh" Comparison of strength between Retempered concrete of two different grades"The Indian Concrete Journal, September 2016, Vol. 90, Issue 9, pp.22-24
[4]. A.R. Pethkar "Retempering of Mortar" volumes 6 Issue 3 Feb. 2016 IJIET ISSI: 2319-1058
[5]. A. M. Alhozaimy, "Effect of retempering of R.M.C. in Hot- dry environments Cement &concrete composites"29(2007) 124-127

Abstract: The satisfactory performance of the pavement will result in higher savings in terms of vehicle operating costs and travel time, which has a bearing on the overall economic feasibility of the project, thorough analysis of the existing pavement is greatly required at this point of time, as an excessive amount of vehicle loads is passing through the project and it is unknown whether or not the road pavement might sustain its structural integrity. The structural integrity of road is depending upon various components of road pavements. In this paper we attempt to give all the requirements & standards of various components of flexible pavements with their test method given by I.S. & minimum required frequency test to be conducted..

Keywords: Flexible Pavement, IS Specifications

[1]. Highway engineering by S.K.KHANNA,
[2]. C.E.G. JUSTO and A.VEERARAGAVAN. text book.
[3]. Principles and practice of highway engineering by L.R KADIYALI, and N.B LAL text book.
[4]. Ministry of road transport and highways (MORTH). Fifth revision.
[5]. Indian road congress (IRC).