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M. Vijaya Sekhar Reddy ¹, I.V. Ramana Reddy ², K. Madan Mohan Reddy ¹, N. Krishna Murthy ³, P. Ramesh ⁴

Affiliations
1 Department of Civil Engineering, Srikalahasteeswara Institute of Technology, Srikalahasti, AP, IN
2 Department of Civil Engineering, Sri Venkateswara University College of Engineering, Tirupati, AP, IN
3 Engineering Department, Yogi Vemana University, Kadapa, IN
4 Department of Civil Engineering, Sri Vidyanikethan Engineering College, Rangampeta, Tirupati, AP, IN

Abstract

Portland cement has been a very satisfactory hydraulic binder for structural applications for a long time now. However there are many new issues stemming from its ever increasing use. Sustainable development today demands development of new concrete technologies, which use less natural resources and energy, and generate less CO2, without compromising on strength and durability properties. Supplementary Cementing Materials (SCMs) such as Flyash, Blast Furnace Slag, Silica Fume and Metakaoline etc., either in singly or in combination, in development of alternate binder systems is thus of economic and ecological significance. In the recent years, use of High Performance Concrete (HPC) in the construction industry as got momentum. For designing HPC, both SCMs and Superplasticizers are essential for the improvement of Workability and Mechanical Properties. The paper presents experimental studies conducted on two grades of HPC mixes of M50 and M60 using mineral and chemical admixtures in various proportions. Overall, the paper highlights the usage of admixtures to achieve high strength concrete mixes and from the experimental investigation it is clear that mineral admixtures contribute effectively a lot not only for achieving durability, also high strength.

Keywords

Supplementary Cementing Materials (SCMs), High Performance Concrete (HPC), Flyash, Blast Furnace Slag, Silica Fume, Metakaoline.

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M. Vijaya Sekhar Reddy ¹, I. V. Ramana Reddy ², K. Madan Mohan Reddy ¹, N. Krishna Murthy ³, T. Venumadhav ⁴

Affiliations
1 Department of Civil Engineering, Sri kalahasteeswara Institute of Technology, Srikalahasti, AP, IN
2 Department of Civil Engineering, Sri Venkateswara University College of Engineering, Tirupati, AP, IN
3 Engineering Department, Yogi Vemana University, Kadapa, AP, IN
4 Department of Civil Engineering, Audi Sankara College of Engineering, Gudur, AP, IN

Abstract

This paper presents the evaluation of mechanical properties of binary blended concrete. Binary blended concrete have been developed by the individual replacement of Supplementary Cementing Materials (SCM's) like Fly-ash, Silica fume and Metakaoline. The results of binary blended concrete are compared with those of control concrete. The main purpose of this investigation is to develop confidence among user agencies in India to use mineral and chemical admixtures in a desirable proportion in most of the construction works. The paper presents experimental studies conducted on M₃₀ grade of concrete using SCMs and chemical admixtures in various proportions. The cubes and cylindrical specimens after de-moulding were stored in curing tanks and on removal of cubes and cylinders from water the compressive strength and split tensile strength were conducted at 7days, 28days, 90 days and 180 days. The test results were compared with individual percentage replacements of SCMs for M₃₀ grade concrete with and without chemical admixture.

Keywords

Supplementary Cementing Materials (SCMs), Binary Blended Concrete, Compressive Strength, Split Tensile Strength, Flyash (FA), Silica Fume (SF), Metakaoline.

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M. Vijaya Sekhar Reddy ¹

Affiliations
1 Department of Civil Engineering, Sri Kalahastheeswara Institute of Technology, Srikalahasti, Andhra Pradesh, IN

Abstract

The February 2007 report issued by the International Panel on Climate Change (IPCC) has started in no uncertain terms that global warming is no longer an issue that has to be debated. According to the report, global warming is here, and drastic actions are needed for the long term sustainable of our environment. In these contexts that this paper discusses the role of supplementary cementing materials as partial replacement for cement in concrete in reducing green house gas emissions. In the new millennium, concrete incorporating self-curing agents will represent a new trend in the concrete construction. Curing of concrete plays a major role in developing the concrete microstructure and pore structure, and hence improves its durability and performance. Due to the high alkalinity of concrete it has always been susceptible to acid attack. Hence, in this investigation an attempt was made in order to know the behavior of Concrete specimens curing with acids such as HCL, Alkaline such as NaOH and sulphate solution MgSO₄ and Na₂SO₄.

In the last decade the use of Supplementary Cementing Materials (SCMs) has become an integral part of high strength and high performance concrete mix design. The addition of SCM to concrete reduces the heat of hydration and extends the service life in structures by improving both long term durability and strength. Some of the commonly used SCMs are Flyash, Silica fume and Metakaoline. This paper presents results of the durability characteristic properties of M₃₀ grade of Concrete with and without SCMs and Superplasticizers.

Keywords

Supplementary Cementing Materials (SCMs), Superplasticizer, Durability, Acid Test, Alkaline Test, Sulphate Attack.

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M. Vijaya Sekhar Reddy ¹, I. V. Ramana Reddy ², K. Madan Mohan Reddy ¹, C. M. Ravi Kumar ³, K. Chandra Sekhar Reddy ⁴

Affiliations
1 Department of Civil Engineering, Srikalahasteeswara Institute of Technology, Srikalahasti, AP, IN
2 Department of Civil Engineering, Sri Venkateswara University College of Engineering, Tirupati, AP, IN
3 Department of Civil Engineering, VTUBTDC, Davanagere, Karnataka, IN
4 Department of Civil Engineering, Siddharth Institute of Engineering & Technology, Puttur, Chittoor, A.P, IN

Abstract

In today's competitive environment it is becoming important to reduce the construction cost in one or other way. Now a day's OPC is widely used and it is the costly ingredients in the production of concrete. However many countries have severe shortage of cement although there requirements are vast. The manufacture of OPC is expensive and skill intensive process, besides polluting the environment heavily production is associated with the emission of carbon dioxide which is a significant source of global warming. Pozzolanic materials are widely used in concrete and mortars for various reasons particularly for reducing the amount of cement required for making concrete and mortar which lead to a reduction in construction cost. This paper presents the results of study under taken to investigate the feasibility of using Supplementary Cementing Materials (SCMs) as partial replacements of cement. The effects of replacing cement by these SCMs on compressive strength, split tensile strength are evaluated in this work. Both compressive and spilt tensile strength is evaluated at 7days, 28 days, 90 days and 180 days.

Keywords

Supplementary Cementing Materials (SCMs), Compressive Strength, Split Tensile Strength, Flyash (FA), Silica Fume (SF), Metakaoline.

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M. Vijaya Sekhar Reddy ¹, K. Ashalatha ²

Affiliations
1 Department of Civil Engineering, Srikalahasteeswara Institute of Technology, Srikalahasti, Andhra Pradesh,, IN
2 Department of Civil Engineering, Srikalahasteeswara Institute of Technology, Srikalahasti, Andhra Pradesh, IN

Abstract

Concrete has today very demanding performance requirements. The concrete durability crisis which started to attract public attention forced the engineers to think about the performance of concrete proper mix design and careful construction using the best available materials and technologies are necessary to achieve quality concrete structures. The February 2007 report issued by the International Panel on Climate Change (IPCC) has started in no uncertain terms that global warming is no longer an issue that has to be debated. According to the report, global warming is here, and drastic actions are needed for the long term sustainability of our environment. Curing of concrete plays a major role in developing the concrete microstructure and pore structure and hence improves its durability and performance. It is in this context that this paper discusses the role of supplementing cementing materials as partial replacement for cement in concrete in reducing green house gas emissions. In the last decade the use of Supplementary Cementing Materials (SCM) has become an integral part of high strength and high performance concrete mix design. The addition of SCM to concrete reduces the heat of hydration and extends the service life in structures by improving both long term durability and strength. The addition of SCM to concrete reduces the heat of hydration and extends the service life in structures by improving both long-term durability and strength. Some of the commonly used SCM’s are Flyash, Silica fume, Blast furnace slag and Metakaoline. This paper presents the results of the durability characteristic properties of M30 grade of concrete without superplasticizer. The durability was evaluated using Rapid Chloride Permeability Test.

Keywords

Standard Concrete, Supplementary Cementing Materials (SCMs), Durability, Rapid Chloride Permeability Test.

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M. Vijaya Sekhar Reddy ¹, M. Madhuri ², K. Sasi ², K. Ashalatha ²

Affiliations
1 Department of Civil Engineering , Srikalahasteeswara Institute of Technology, Srikalahasti, Andhra Pradesh, IN
2 Department of Civil Engineering, Srikalahasteeswara Institute of Technology, Srikalahasti, Andhra Pradesh,, IN

Abstract

The plain concrete possesses a very low tensile strength, limited ductility and little resistance to cracking. The addition of small, closely spaced and uniformly dispersed fibres to concrete would act as crack arrester and would substantially improve its static and dynamic properties. This paper presents the variation in strength characteristics of fibre bricks by varying the percentage of fibres and class F flyash. the percentage of fibres is varied from 0.25% and 0.5% An effort for an alternate approach in the experimental manufacturing of brick was accomplished by using various supplementary cementing materials like class F Fly ash, Hydrated lime and fibres such as jute and banana are used as key ingredients in the present investigation. Recycling such wastes by utilizing them into building materials is a moderate solution for the environmental pollution issues. Much of an emphasis is laid on energy saving and economy. In this experimental work an attempt is made for such an alternate approach.

Keywords

Natural Fibre, Jute Fibre, Banana Fibre, Fly Ash Bricks, Split Tensile Strength.

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M. Vijaya Sekhar Reddy ¹, K. Sasi ¹, K. Ashalatha ¹, M. Madhuri ¹

Affiliations
1 Department of Civil Engineering, Srikalahasteeswara Institute of Technology, Srikalahasti, Andhra Pradesh, IN

Abstract

Ordinary Portland cement is recognized as a major construction material throughout the world. Researchers all over the world today are focusing on ways of utilizing either industrial or agricultural waste, as a source of raw materials for industry. This waste, utilization would not only be economical, but may also result in foreign exchange earnings and environmental pollution control as industrial wastes, such as blast furnace slag, sugar cane bagasse ash, ground nut shell ash, fly ash and silica fume are being used as supplementary cementing materials (SCMs). The utilization of industrial and agricultural waste produced by industrial process has been the focus of waste reduction research for economical, environmental, and technical reasons. The present study is aimed at ground nut shell ash (GSA), with partial replacement of cement. The replacement is done at various percentages like 0%, 5%, 10%, 15% and its effect on properties of concrete was investigated. Fresh and hardened properties were exercised with various replacement levels. The study indicated that ground nut shell ash can effectively be used as cement replacement (up to 10%) without substantial change in strength.

Keywords

Workability, Compressive Strength, Ground Nut Shell Ash, Supplementary Cementing Materials, Super Plasticizer.

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