Concrete Engineering

By
Sagar Sanjay Phatale
Department of Civil Engineering
University of Texas at Arlington

High performance concrete provides high durability, strength, low water-cement ratio and longer life span of the structure. Special ingredients such as plasticizers, optimum aggregate size and fiber steel reinforcement are used to make this type of concrete admixture. This type of concrete type is used in special and complex construction structure such as bridges and tunnels. High performance concrete also helps in reducing the duration of the project, as there is low water cement ratio in making the admixture for the concrete. This type of concrete is useful for fast track construction where owner required the possession of the property as soon as possible. High performance concrete have several advantages over traditional Portland cement concrete.

First, high performance concrete provides better strength and durability. Water cement ratio majorly affect the workability of the concrete (Naik et. Al., 2012). According to Naik et al., (2012, p. 463), increase in the water cement ratio, which can be obtained by increasing the water content in the concrete admixture, increases the workability and slump ratio of the concrete.

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By
Vikramaditya Pandey

Abstract
Floating concrete is a fluid mixture of density less than water, which is suitable to build floating structures, reducing the consumption of land for buildings. This project report addresses the procedure of preparation of mix proportion of floating concrete, materials used & various test results of compressive strength at the age of 7 days & flow, for acceptance of this concrete. Also, it presents an application of this concrete for canoe construction along with a light weight but, strong reinforcement. Despite the self weight of the canoe, it can bear a certain amount of external load.

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By
M.RAJAGOPAL REDDY 1, P.RAJESH 2
1- Post Graduate student, Department of civil Engineering,VFSTR university , Vadlamudi.
2-Assistant Professor, Department of civil Engineering, VFSTR university, Vadlamudi.

ABSTRACT
The FLAT SLAB SYSTEM being used in majority of the constructions. It elevates more clear space in architecting the construction design in easy manner and duration of construction would be short due to the flat slabs size. Compare to the traditional concrete construction slab system is more viable due to the fact that it avoids the heavy beams, which are the big vulnerability in case of earthquakes. Objective of this paper is to investigate the behavior of flat slab system in few different use cases.

1. Flat slab structure without drop.
2. Flat slab structure with column drop.
3. Flat slab structure with shear wall.
4. Flat slab structure with column drop and shear wall together through response spectrum method by using ETABS software.

The behavior of flat slab is investigated in terms of the following factors:
1. Frequency
2. Base Shear
3. Storey level accelerations

Also most severe problem in flat slabs as follows:
1. Failure punching shears
2. Shear stresses during ground unbalance
3. Slab column connections to brittle punching shear stresses during earthquakes.

Also this paper investigates about the combinations that can produce less punching shear at slab column joint.

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By
Pravesh Shukla

Abstract
The utilization of industrial and agricultural waste produced by industrial process has been the focus on waste reduction research for economical, environmental and technical reasons. SCBA is a fibrous waste product of the sugar refining industry, along with ethanol vapour. Bagasse ash mainly contains aluminium ion and silica. The use of SCBA as a pozzolonic material for producing high strength concrete. OPC is partially replaced with finely SCBA. At present the disposal of waste tyre is becoming a major waste management problem in the world. In this project, the bagasse ash has been chemically and physically characterized and partially replaced in the ratio of 0%, 5%, 15% and 25% by weight of cement in concrete. The mix proportion for M30 grade concrete was derived. Rubber tyre waste has been used as coarse aggregate with replacement of conventional coarse aggregate and it is taken as constant of 10%.

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By
Shubham Sunil Malu

1.0 INTRODUCTION:
Cracking is one of the major issues in concrete. Since concrete has various physical and chemical properties it is prone to cracking. Its elimination is not possible totally but it can be restricted or reduced to a certain extent. Mostly, cracking goes on a microscopic scale and does not appear visibly as a fault. If the cracking goes on a macroscopic scale it can result in loss of strength, stability and durability. It can also cause decrease in sound insulation and overall efficiency besides affects aesthetics to a greater extent.

The main causes of cracking are as follows:

• Ageing – Carbonation
• Foundation problems
• Weathering Actions
• Improper or modified use of the structure
• Poor maintenance
• Progressive loading
• Deficiencies in design
• Poor quality of concrete material
• Improper concrete mix
• Movement of concrete arising from physical properties
• Poor workmanship and negligence
• Over trowelling and impermeable formwork
• Reduced continuity of the structural member
• Defects and errors in construction practices
• Improper structural repairs or modification
• Chemical attacks by Chlorides and Sulphates
• Differential thermal stress – Heat of hydration of cement

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By
Shubham Sunil Malu

ABSTRACT:
A concrete plant, also known as batch plant is device that combines various ingredients to form concrete. In general, it is a process of combining all ingredients of concrete as per the mix design. Batching and mixing are extremely important parts of mortar and concrete manufactures they influence properties of concrete both in plastic as well as in hardened stages. Also, it is one of the important processes, which is to be done to obtain a quality concrete. Many processes are carried out in various parts of the world with many changes and different equipment. There are various types of batching and mixing equipment and methods that is to say from manual to most sophisticated computerized batching and mixing. Mechanization improves quality of batching and mixing, its speed and thereby can most often result in economy.There are number of factors which are to be considered while doing the process which are discussed in this paper. Moreover, the machinery, which is to be required while making concrete or for batching process and discharging and unloading of the mixture, are also discussed in brief.
1.0 INTRODUCTION:

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By:
Shubham Sunil Malu.

ABSTRACT:
With the growth of construction industry there is need to give quality in it. Many of the projects fail in construction field because of improper results and improper testing on site. One of the basic and important test is compressive test which should be done carefully since it is taken as the backbone of all tests of civil engineering related to concrete. Compression test is required almost in every project since it gives us a brief idea of the grade and type of concrete. Many of them do small mistakes in these which includes the different exclusion of different parameters of concrete, improper procedure for filling and compacting concrete, wrong methods of testing of concrete and many more. This paper contains all the necessary parameters, equipment and the acceptance criteria of the test. It also includes procedure for filling and compacting concrete as well as methods of testing of concrete.

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By
Sourav Dutta
Manager-Civil

What is slab?
A RCC (Reinforced Cement Concrete) slab is the most common structural element of any type of building. Horizontal slabs, typically between 4 and 20 inches (100 and 500 millimeters) thick, are most often used to construct floors and ceilings.Here discussion on “flat slab” has not been considered.

Typical loads to be considered for slab design
(i) Dead load: Any permanent load acting on the slab e.g. self-weight of slab, weight of floor finish & plaster

(ii) Live Load: Any non-permanent or moving load e.g. weight of occupants, furniture, and partitionon the slab

(iii) Snow load (if any)

Note: Earthquake and Wind loads are not considered in the design of slabs.

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By
KAUSHAL KISHORE
Materials Engineer, Roorkee

While carrying out Concrete Mix Design, there are chances that we do not consider some technical points resulting the production of poor quality concrete. This is best illustrated by the following two examples. The I^st mix design is carried out carelessly, where as the 2^nd mix design is worked out taking into consideration all technical points. In both mix design examples the materials and requirements are same as given below:

1. Cement, PPC, 7-days strength 36.5 N/mm² and 28-days strength 46.8 N/mm². Specific gravity 3.0
2. Aggregates grading are as given below:

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By
Sourav Dutta
Manager-Civil

Introduction
There are a number of ways in which the superstructure can be built. In areas where average to good quality bricks are available, the walls of houses for two to three storeyed constructions can be built out of bricks with the slabs, lintels, chajja etc. in reinforced concrete. Such construction is termed as load bearing construction (Fig 1). This is essentially because the entire load coming from the slabs, beams, walls etc is transmitted to the foundation through the brick walls.

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