scholarly journals Evaluation of the Fresh and Hardened Properties of Steel Fibre Reinforced Self-Compacting Concrete Using Recycled Aggregates as a Replacement Material

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
N. Nalanth ◽  
P. Vincent Venkatesan ◽  
M. S. Ravikumar
Keyword(s):  
Construction Materials ◽  
Recycled Aggregates ◽  
Partial Replacement ◽  
Self Compacting Concrete ◽  
Rapid Urbanization ◽  
Coarse Aggregates ◽  
Mix Proportion ◽  
Materials Recycling ◽  
Considerable Work ◽  
Day By Day

In this world of rapid urbanization the demand for natural construction materials is increasing day by day which has created a necessity for alternative construction materials. Recycling of materials is a possible way of eradicating the acute shortage of materials. Considerable work has been done in the area of self-compacting concrete by partial replacement of coarse aggregates (CA) with recycled coarse aggregates (RCA) obtained from construction and demolition debris. The present study has been done by adding steel fibers to concrete in a view of improving the mechanical properties of SCC so that it can be applied in beam column joints. An ideal mix proportion was arrived at, as a result of repeated trials and specimens that were cast and cured. The compression, tensile, and flexural strength parameters were determined and the result has been presented. The results obtained reveal that brick bats in combination with steel fibres may be used extensively in SCC.

scholarly journals Effect of Fly Ash on the Compressive Strength of Green Concrete

2020 ◽  
Vol 10 (3) ◽  
pp. 5728-5731 ◽  
Author(s):  
S. A. Chandio ◽  
B. A. Memon ◽  
M. Oad ◽  
F. A. Chandio ◽  
M. U. Memon
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Recycled Aggregates ◽  
Waste Materials ◽  
Partial Replacement ◽  
Equal Proportion ◽  
Standard Size ◽  
Green Concrete ◽  
Coarse Aggregates ◽  
Management Issues

This research paper aims at investigating the effects of fly ash as cement replacement in green concrete made with partial replacement of conventional coarse aggregates with coarse aggregates from demolishing waste. Green concrete developed with waste materials is an active area of research as it helps in reducing the waste management issues and protecting the environment. Six concrete mixes were prepared using 1:2:4 ratio and demolishing waste was used in equal proportion with conventional aggregates, whereas fly ash was used from 0%-10% with an increment of 2.5%. The water-cement ratio used was equal to 0.5. Out of these mixes, one mix was prepared with all conventional aggregates and was used as the control, and one mix with 0% fly ash had only conventional and recycled aggregates. The slump test of all mixes was determined. A total of 18 cylinders of standard size were prepared and cured for 28 days. After curing the compressive strength of the specimens was evaluated under gradually increasing load until failure. It is observed that 5% replacement of cement with fly ash and 50% recycled aggregates gives better results. With this level of dosage of two waste materials, the reduction in compressive strength is about 11%.

Experimental Research on Compressive Strength of Self-Compacting Concrete with Recycled Coarse Aggregates

2011 ◽  
Vol 306-307 ◽  
pp. 1084-1087 ◽  
Author(s):  
Jing Li ◽  
Xian Feng Qu ◽  
Lin Fu Wang ◽  
Chong Qing Zhu ◽  
Juan Li
Keyword(s):  
Compressive Strength ◽  
Design Method ◽  
Self Compacting Concrete ◽  
Longitudinal Splitting ◽  
Coarse Aggregates ◽  
Hydraulic Concrete ◽  
Mix Proportion ◽  
Splitting Failure ◽  
Concrete Blocks ◽  
Waste Solid

In order to study cubic compressive strength of recycled coarse aggregates-filled concrete systematically, recycled coarse aggregates with the particle size from 50 to150mm are made from waste solid contents, which are artificially broken from abandoned rubble and concrete blocks. Based on the mix proportion design method of ordinary concrete and test code for hydraulic concrete, 3 groups of recycled coarse aggregates-filled concrete cubic specimens were prepared and the compressive strength of the specimens were tested. The results showed that basic failure pattern of recycled coarse aggregates-filled concrete are longitudinal splitting failure, and that cubic compressive strength is higher than that of self-compacting concrete.

scholarly journals Compressive Strength of Concrete with Construction and Demolition Waste and m-SAND using Additives

2019 ◽  
Vol 8 (2S10) ◽  
pp. 935-937
Keyword(s):  
Compressive Strength ◽  
Green Building ◽  
Cost Effective ◽  
Construction And Demolition Waste ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Demolition Waste ◽  
Rapid Urbanization ◽  
Manufactured Sand ◽  
Coarse Aggregates

Construction and Demolition wastes(C&D wastes) are generated in all cities of the world due to rapid urbanization. Disposing C & D waste these days is a costly affair, and raises environmental issues. Hence an attempt is made to reuse the demolished concrete as a partial replacement of natural coarse aggregates. Also due to ban of sand mining by local authorities, the cost of natural fine aggregate is very high and itself becoming a scarce material. Hence crushed stone aggregates called manufactured sand (m sand) is used, totally replacing natural fine aggregates. This concept is found to be cost effective, minimizes disposal of C & D wastes, and leads towards Green Building Concepts. Compression test on M40 concrete cubes of size 150mmx150mmx150mm are conducted at end of 7 days and 28days. Mix design for M40 concrete is made in accordance to IS: 10262-2019 with water cement ratio of 0.45 using 53 Grade Ordinary Portland cement. Superplasticizer (LIQUIFIX) is used to enhance workability. Nano Silica (NS)(1.5% by weight of cement),Wollastonite powder(WP)(10%by weight of cement) and Basalt fibres(BF)(1% by weight of cement) are added as additives. It is observed, that compressive strength of 7 days and 28 days cured samples is 25% more with the addition of all three additives compared to samples without additives. Hence the loss of compressive strength obtained by using demolished concrete as aggregates and m sand in concrete is regained with the addition of additives.

scholarly journals Mechanical Properties of Geopolymer Concrete Made With Partial Replacement of Coarse Aggregate by Recycled Aggregate

2019 ◽  
Vol 9 (1) ◽  
pp. 2301-2304 ◽  
Keyword(s):  
Mechanical Properties ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Coarse Aggregate ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Partial Replacement ◽  
Geopolymer Concrete ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates

Construction is the one the fast growing field in the worldwide. There are many environmental issues connected with the manufacture of OPC, at the same time availability of natural coarse aggregate is getting reduced. Geopolymer binder and recycled aggregates are promising alternatives for OPC and natural coarse aggregates. It is produced by the chemical action of inorganic molecules and made up of Fly Ash, GGBS, fine aggregate, coarse aggregate and an alkaline solution of sodium hydroxide and sodium silicate. 10 M sodium hydroxide and sodium silicate alkali activators are used to synthesis the geopolymer in this study. Recycled aggregates are obtained from the construction demolished waste. The main focus of this work is to find out the mechanical properties of geopolymer concrete of grade G40 when natural coarse aggregate(NCA) is replaced by recycled coarse aggregate in various proportions such as 0%, 10%, 20%, 30%,40% and 50% and also to compare the results of geopolymer concrete made with recycled coarse aggregates(RAGPC) with geopolymer concrete of natural coarse aggregate(GPC) and controlled concrete manufactured with recycled aggregates(RAC) and controlled concrete of natural coarse aggregates(CC) of respective grade. It has been observed that the mechanical properties are enhanced in geopolymer concrete, both in natural coarse aggregate and recycled coarse aggregate up to 30% replacement when it is compared with the same grade of controlled concrete.

INVESTIGATION OF EFFECTS OF RECYCLED AGGREGATES AND BLAST FURNACE SLAG ON PROPERTIES OF SELF-COMPACTING CONCRETE

2020 ◽  
Vol XVII (3) ◽  
pp. 1-14
Author(s):  
Leila Shahryari ◽  
Maryam Nafisinia ◽  
Mohammad Hadi Fattahi
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Recycled Aggregates ◽  
Test Results ◽  
Self Compacting Concrete ◽  
Coarse Aggregates ◽  
Fine Aggregates ◽  
Negative Effect ◽  
Furnace Slag

The effects of simultaneous use of recycled aggregates and ground blast furnace slag as a percentage of cement-constituting materials on different properties of fresh self-compacting concrete (SCC) are investigated in this study. To this end, three series of SCC mixtures with a fixed volume of cement paste equalling 380 ltr/m3 (2.36 gal/ft3) and the replacement ratio of coarse aggregates (fifty percent and one hundred percent) and total aggregates (zero percent, fifty percent and one hundred percent) were prepared. The water content ratios in the first, second and third series were 0.4, 0.45, and 0.5, respectively. The results of the compressive strength tests for 7-day, 14-day and 28-day cubic specimens and compressive strength and Brazilian test results for 28-day cylindrical specimens were used as control parameters governing the SCC resistive quality. The results of fresh SCC tests (including slump-flow and T50 tests, V-funnel test, and L-box test) showed that the negative effect of recycled fine aggregates on fresh SCC properties is significantly more than that of recycled coarse aggregate. However, recycled SCC with acceptable properties can be obtained with a slight increase in the amount of superplasticisers used in the presence of slag.

scholarly journals Effect of Design Parameters on Compressive and Split Tensile Strength of Self-Compacting Concrete with Recycled Aggregate: An Overview

2021 ◽  
Vol 11 (13) ◽  
pp. 6028
Author(s):  
P. Jagadesh ◽  
Andrés Juan-Valdés ◽  
M. Ignacio Guerra-Romero ◽  
Julia M. Morán-del Morán-del Pozo ◽  
Julia García-González ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Design Parameters ◽  
Fine Aggregate ◽  
Self Compacting Concrete ◽  
Split Tensile Strength ◽  
Coarse Aggregates ◽  
Fine Aggregates

One of the prime objectives of this review is to understand the role of design parameters on the mechanical properties (Compressive and split tensile strength) of Self-Compacting Concrete (SCC) with recycled aggregates (Recycled Coarse Aggregates (RCA) and Recycled Fine Aggregates (RFA)). The design parameters considered for review are Water to Cement (W/C) ratio, Water to Binder (W/B) ratio, Total Aggregates to Cement (TA/C) ratio, Fine Aggregate to Coarse Aggregate (FA/CA) ratio, Water to Solid (W/S) ratio in percentage, superplasticizer (SP) content (kg/cu.m), replacement percentage of RCA, and replacement percentage of RFA. It is observed that with respect to different grades of SCC, designed parameters affect the mechanical properties of SCC with recycled aggregates.

scholarly journals Experimental study of optimal self compacting concrete with spent foundry sand as partial replacement for M-sand using Taguchi approach

2016 ◽  
Vol 11 (1) ◽  
pp. 119-130
Author(s):  
D.B. Nirmala ◽  
S. Raviraj
Keyword(s):  
Partial Replacement ◽  
Taguchi Approach ◽  
Test Results ◽  
Self Compacting Concrete ◽  
Foundry Sand ◽  
Control Factors ◽  
Technical Requirements ◽  
Mix Proportion ◽  
Super Plasticizer ◽  
Optimal Mix

Abstract This paper presents the application of Taguchi approach to obtain optimal mix proportion for Self Compacting Concrete (SCC) containing spent foundry sand and M-sand. Spent foundry sand is used as a partial replacement for M-sand. The SCC mix has seven control factors namely, Coarse aggregate, M-sand with Spent Foundry sand, Cement, Fly ash, Water, Super plasticizer and Viscosity modifying agent. Modified Nan Su method is used to proportion the initial SCC mix. L18 (21×37) Orthogonal Arrays (OA) with the seven control factors having 3 levels is used in Taguchi approach which resulted in 18 SCC mix proportions. All mixtures are extensively tested both in fresh and hardened states to verify whether they meet the practical and technical requirements of SCC. The quality characteristics considering “Nominal the better” situation is applied to the test results to arrive at the optimal SCC mix proportion. Test results indicate that the optimal mix satisfies the requirements of fresh and hardened properties of SCC. The study reveals the feasibility of using spent foundry sand as a partial replacement of M-sand in SCC and also that Taguchi method is a reliable tool to arrive at optimal mix proportion of SCC.

scholarly journals An Experimental Research On Partial Replacement Of Coarse Aggregate with Recycled Aggregate and Fine Aggregate with Granite Powder

2019 ◽  
Vol 8 (9S2) ◽  
pp. 72-77
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Age Group ◽  
Split Tensile Strength ◽  
Coarse Aggregates ◽  
Granite Powder

Now a days increase in population increases the demand of concrete for construction purpose and Aggregates are the important constituents in concrete.Re-use of demoliation waste avoids the problem of waste disposal and is also helpful in reducing the gap between demand and supply of fresh aggregates. This research deals with partial replacement of natural coarse aggregates (NCA) with recycled coarse aggregates (RCA) of age group 30 years and 35 years in different proportions like 20%, 30%, 40% . For this, M20 grade of concrete is adopted. Curing of specimens were done for 7days and 28 days to attain the maximum strengths. Partial replacement of fine aggregate with Granite powder at 5%, 10%, 15% were done to reduce the waste percentage as well to gain more strength. After casting the specimens of RCA with Granite powder replacement, curing was done and the specimens were tested for compressive and tensile strengths. Obtained results of compressive and tensile strengths of RCA concrete mix were compared with conventional concrete. In this direction, an experimental investigation of compressive and tensile strength was undertaken to use RCA as a partial replacement in concrete. It was observed that the concrete with recycled aggregates of 30years and 35years age group achieved maximum compressive strength of 29.03 N/mm2 , 28.96 N/mm2 and tensile strength of 11.91 N/mm2 , 10.34 N/mm2 were obtained at 40%replacement of RCA respectively. It is found that the compressive strength and Split tensile strength of RAC with copper slag was increased 8.20% and 2.90% when compared with the RAC.

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