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Concrete Engineering

Study On Behaviour Of Concrete Partially Replacing Quartz Sand As Fine Aggregate

BY
E.Divya1 , R.Shanthini2, S.Arulkumaran3
Student, Dept. of civil engg., IFET college of engg., India1, 2
Asst. professor, Dept. of civil engg., IFET college of engg., India3

ABSTRACT
The use of quartz sand as replacement for sand is an economical solution for making the concrete resistant to weathering. The paper presents a concrete mix design procedure for partial replacement of sand with quartz sand. Present method was performed to evaluate the additional compressive, flexural strength with higher slump over conventional concrete in which sand is replaced with 0%, 25%, 50% and 100% of quartz sand by weight with 1% super plasticizers. The research also revealed that there is possibility of replacing fine aggregate with quartz sand in the production of structural concrete. The mix proportion adopted was 1:1.7:3 as per 10262:2009. Compressive and flexural strength tests were carried out to evaluate the strength properties of concrete at the age of 7 and 28 days. Modulus of elasticity tests were carried out at the age of 28 days.

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CONCRETE QUALITY CONTROL DURING CONSTRUCTION

By
1) KAUSHAL KISHORE
Materials Engineer
Roorkee
Kaushal Kishore is retired from IIT, Roorkee and now a Consulting Materials Engineer. He has over 50 years of experience in all types of Concrete Mix Design.

2) RAKESH SHARMA
Vice President Project
Supertech Limited
Rakesh Sharma is Vice President Project of M/s Supertech Limited. He has 28 years of experience in Construction.

I.T. Park, Doon Square Mall at Dehradun, Uttarakhand is being constructed by M/s Supertech Ltd. For this site M-30 grade of concrete suitable for pumped concrete is required. Aggregates for construction was stored at site. Its analysis report is given in Table 2.

For laboratory trial 5 brands of PPC cement bags were taken from local market. They were identified as cement brand, 1, 2, 3, 4 and 5. Two reputed brands of normal superplasticizers based on sulphonated naphthalene formaldehyde (SNF) were taken for trials. They were identified as SP (A) and SP (B) to find their compatibility with the given 5 brands of PPC cement identified as cement brand 1, 2, 3, 4 and 5.

COMPATIBILITY
The behavior of concrete in the presence of superplasticizers is related to the amount and type of sulfate added to the clinker. The rheological and setting Behavior are changed depending on whether the sulfate is added as anhydrite, hemihydrates, or gypsum. The difference are explained by the different rates of dissolution of these sulfates.
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Concrete Strength Acceptance Criteria IRC:15-2011

By
KAUSHAL KISHORE
Materials Engineer, Roorkee

For concrete roads, flexural strength of concrete is the design criteria. For all major projects, flexural strength of the mix shall be determine by third point loading of flexural beams size 150 mm x 150 mm x 700 mm as per IS: 516. Determination of flexural strength by correlating with cube strength (compressive strength) shall not be allowed for major projects, as the correlation is not well established.

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Concrete Strength Acceptance Criteria IS:456-2000

By
KAUSHAL KISHORE
Materials Engineer, Roorkee

Strength of concrete is commonly considered its most valuable property, although in many practical cases, other characteristics, such as durability and permeability, may in fact be more important. However, the strength of concrete is almost invariably a vital element of structural design and is specified for compliance purposes.

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Mix Design and Pumped Concrete

By
KAUSHAL KISHORE
Materials Engineer, Roorkee

A simple method of concrete mix design for pumpable concrete based on an estimated weight of the concrete per unit volume is described in the paper. The tables and figures presented are worked out by the author from a wide range of Indian materials. The method is suitable for normal weight concrete with admixture.

INTRODUCTION
Pumped concrete may be defined as concrete that is conveyed by pressure through either rigid pipe or flexible hose and discharged directly into the desired area. Pumping may be used for most all concrete construction, but is especially useful where space or access for construction equipment is limited.
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