globe in order to improve the performance of concrete in terms of strength and durability. Consequently concrete has no longer remained a construction material but has rather becomes an engineered custom tailored material with several new constituents to meet the specific needs of construction industry. The growing use of concrete in special architectural configurations and closely spaced reinforcing bars have made it very important to produce concrete that ensures proper filling ability, better structural
(3) Slump Test Aim:- To determine the workability or consistency of concrete mix prepared at the laboratory or the construction site during the progress of the work. It is used conveniently as a control test and gives an indication of uniformity of concrete from batch to batch. Apparatus:- (1) Metallic mould in the form of a frustum of a cone with internal dimensions as follow: • Bottom diameter = 20 cm • Top dia. = 10 cm • Height = 30 cm The bottom and top ends of the mould are open, parallel
properties of concrete and improve the quality of concrete during mixing, transportation, placing and curing. Some of the chemicals admixtures are: 1. Air-entrainment 2. Water-reducing 3. Set-retarding 4. Accelerating 5. Super-plasticizers 6. Corrosion-inhibitors 3.6.2 Mineral Admixtures These are inorganic materials that also have pozzolanic or latent hydraulic properties. These very fine-grained materials are added to the concrete mix to improve the properties of concrete (mineral admixtures)
3.2.3.6 Aggregate Impact Value test as per IS: 2386- 4 (1963) This test was performed to determine the aggregate impact value of coarse aggregates. Impact testing machine was used. Cup of the machine was firmly fixed. Sample was placed in it and compacted with the help of tamping rod. 15 blows of hammer were given from 380 mm height. Sample is then sieved from 2.36 IS sieve. Material retained was weighed. Table 3.17:- Aggregate Impact Value Result Observations Sample 1 Sample 2 Weight of dry sample
Mechanical Properties of colored concrete 2.6.1 Fresh properties of colored concrete A) Fluidity of cement mortar Hyun-SooLeea, et al. studied effects of inorganic pigments on the fluidity of cement mortar. The most commonly used in concrete products two types of pigment were used: The first was a Korean product pigment (A) and the second was a German product pigment (Z). The main ingredient of red, yellow, and black pigments is iron oxide (Fe2O3) and that of the green pigment is chrome oxide (Cr2O3)
Discussion Slump Test Two of the slump tests showed true slump in which it just subsides while retaining its overall shape without collapsing. Both of the slumps are within the range of 30mm to 60mm. According to Figure 12, this indicated that degree of workability is medium which makes it suitable for producing normal reinforced concrete. The results also shows that the more water/cement ratio in the mixed concrete, the better the workability as slump increases from 45 to 51mm after
along with cement particles on the surface of the freshly laid concrete A measure of how well concrete will handle freezing and thawing, wetting and drying, and physical wear. The ability of a hardened cement paste retain its volume after setting without delayed destructive expansion The property determining the effort required to manipulate a freshly mixed quantity of concrete with a minimum segregation The ability of fresh concrete to hold all the ingredients together uniformly List of possible
Pervious concrete is different from the conventional concrete. It is defined as “no fines concrete”. The pervious concrete mix contains very little or practically no fine aggregate. Pervious concrete which is also known as the no-fines, porous, gap graded, and porous concrete and enhance porosity concrete has been found to be a reliable storm water management tool. By definition, pervious concrete is a mixture of gravel or granite stone, cement, water, little to no sand (fine aggregate) with or without
Self-compacting concrete (SCC), also known as self-consolidating concrete, is a specialized high performance concrete that does not need to be compacted by vibration as it compacts into every corner and space of a formwork as a result of its own weight. The most laudable property of SCC is that it leaves no void in the formwork, and that too, without the need of mechanical vibration (De Schutter, 2007; Okamura & Ouchi, 2003; Hurd, 2002). SCC, therefore, has superior engineering properties that make
As stated earlier, inductive reasoning is a bottom up approach, the premises provide evidence for the truth of the conclus... ... middle of paper ... ... while there is no certain proof of it. The decision of going forward with the badge of concrete involved error probability and the decision was left inevitably upon the judgement of the acting supervisor. Attempts have been made to show that even if we cannot justify rely on induction by pure reason we have practical or pragmatic reasons in
Introduction High performance concrete is a concrete mixture, which possess high durability and high strength when compared to conventional concrete. This concrete contains one or more of cementious materials such as fly ash, Silica fume or ground granulated blast furnace slag and usually a super plasticizer It comprises of the same materials as that of the conventional cement concrete. The Conventional Portland Cement Concrete Problems • Durability in severe environs (shorter service
In a traditional way, a concrete mix is designed based on the code requirements and recommendations which uses the empirical values obtained from previous experiences. Compressive strength of concrete is determined by conducting standard uniaxial compression test on standard cylindrical sample specimens of ages 7 & 28 days, following the standard procedure and test values are reported in accordance with ASTM and ACI standards . If the strength value obtained from the test is less than the required
Concrete Mix Design: Based on the above data and the requirements that are to be achieved for the construction of the dam are analyzed. Self compacting concrete has been used mostly in the design of major parts of the dam.For the first time China used new type of admixture known as Glenium type PCE admixture (PCE-3) for the mix used in constructing the power house.The SCC mixture contains large content of limestone powder to increase fluidity,cohesiveness and limit heat generation.These materials
In the ever increasing construction industry, concrete forms the basic building block. Concrete consists mainly of three raw materials apart from water. These are cement, coarse aggregate and fine aggregate. Out of these raw materials, cement and coarse aggregate can be easily manipulated to match the needs of how concrete should be made. While as sand, which amounts to about 35% by volume of concrete, is mainly obtained from natural sources like river beds and the quality and texture of sand cannot
Fly Ash Fly ash is a by-product of coal from power stations. It helps to improve the durability of concrete. Through the observation under the SEM test, It can be noticed that the fly ash sample consists of almost regular spherical or cenospheres particles ranging 2 um to 14 um in diameter (Ismail et al., 2007). This is due to the fact that fly ash is produced by fusing small and light particles that remain suspended in the burning chamber but are captured afterwards by electrostatic filtration
2.1.8.4.2. Splitting tensile strength: The splitting tests are well known as indirect tests used for determining the tensile strength of concrete. And sometimes it is referred to as split tensile strength of concrete. The split tensile strength is a more reliable technique to evaluate tensile strength of concrete (lower coefficient of variation) compared to other methods. The split tensile strength specimen of 150 mm diameter and 300 mm or 150 x150 mm cube specimen are placed between two plates with
2.1.8.4.2. Splitting tensile strength: The splitting tests are well known as indirect tests used for determining the tensile strength of concrete. And sometimes it is referred to as split tensile strength of concrete. The split tensile strength is a more reliable technique to evaluate tensile strength of concrete (lower coefficient of variation) compared to other methods. The split tensile strength specimen of 150 mm diameter and 300 mm or 150 x150 mm cube specimen are placed between two plates with
30 minimum Final setting time 600 maximum 2. Water : Water is an important ingredient of concrete as it actually participates in the chemical reaction with cement. Since it helps to from the strength giving cement gel, the quantity and quality of water are required to be looked into very carefully. 3. Aggregates : They are the important constituents of concrete. They give body to the concrete, reduce shrinkage and effect economy. Good
simplest form, a blend of paste, stone, sand and water is a concrete. Concrete is one of the fundamental building block of the civilization, contributing to all the structures across the world. Concrete can be viewed in details in term of its constituent materials, properties, durability and concrete mix design and quality control. Constituent materials are the fundamental materials required to produce concrete. The constituent materials of concrete consist of mainly three materials which are cement, aggregate
accordance with IS 2386-1963. Fine aggregate passing through 4.75mm I.S. sieve and retained on 0.075mm I.S. sieve was used. It confirms to grading zone – II of I.S. 383-1970. The specific gravity and fineness modulus are found to be 2.50 and 2.79. These test results are tabulated in Table 4.1.4. Sieve analysis is carried out and results are shown in Table