Then, we obtain the free-water/ cement ratio from table Figure 1. For OPC ( 7 days ) using crushed aggregate, water/cement ratio = 36 N/mm 2. After that, from the Figure 2, the curve for 42 N/mm 2 at 0.5 free-water ratio is plotted and obtained the free-water ratio is 0.45 at the target mean strength 43.12 N/mm 2.

controls workability of fresh concrete. fine aggregates. washed river sands, particle size that is less than 4.76mm min water-cement ratio max cement content max aggregate -cement ratio max density of concrete. specifications. Workability. determines the case with which a concrete can be mixed, transported, paced, compacted, and finished w

The aggregate to cement ratio is affecting the workability of concrete. When the aggregate to cement ratio increases, there is less cement paste. Therefore, workability is reducing. The reduction of the aggregate to cement ratio leads to an increase in the workability of concrete. Further, this ratio is controlled the mix design to achieve to

More the water content, higher the water/cement ratio, resulting in better workability, but the strength of concrete is reduced. Further approximately it can he assumed that for a given type and grading of aggregate and workability of concrete, the water content is independent of the aggregate/cement ratio.

The main problem in using crushed glass as aggregate in Portland cement concrete are expansion and cracking 1982. Mix design was done for M20 grade of concrete. The mixture was prepared with water to cement ratio of 0.5. The Table 2 and Figure 2 shows the results of workability of concrete with cement replacement by glass powder in

When mortar needs water, it was added to obtain Aggregate Water Cement Water – cement Sample diameter (g) (ml) (g) ratio (mm) (2:1) required workability in experiment, and then depending on the condition of the concrete, its mixture proportions are re- 9000 1000 2000 0.5 72.4 9000 858 2142 0.4 72.4 arranged to keep water – cement ratio

Variation in coarse-aggregate gradation causes changes in the workability of concrete, with relatively lower workability resulting from finer gradings (2, 3). 2. Variation causes changes in the compressive strength of concrete, wiffi grad­ ings having smaller maximum sizes increasing in strength (6). 3.

Variation in coarse-aggregate gradation causes changes in the workability of concrete, with relatively lower workability resulting from finer gradings (2, 3). 2. Variation causes changes in the compressive strength of concrete, wiffi grad­ ings having smaller maximum sizes increasing in strength (6). 3.

This indicates that the concrete mix having water-cement ratio less than 0.45 by weight is not workable and causes honey-comb structure .but amount of water to be added also plays an important role in this Keyword-Concrete mixture, fine aggregate, coarse material, water-cement ratio, workability, strength INTRODUCTION T he concrete, when used

Typically most mixes look to get a ratio of around 0.45 to 0.6 to achieve workable concrete. Aggregates. The size and shape of the aggregates (stones and sand) used in a concrete mix will affect its workability. As aggregate surface area increases, the more cement paste is needed to cover the entire surface of aggregates. So - concrete mixes

The term workability indicates the ease or difficulty with which the concrete is handled, transported and placed. The amount of water present in concrete should be in the proper ratio. Generally, a higher water-cement ratio is required for good workability. In the actual function of water is to lubricate the concrete.

The present study has evaluated the effects of varying water-cement ratio on workability and strength of locally generated steel slag aggregate (SSA) concrete. Tested samples include 150 mm concrete cubes and cylinder samples with 150 mm diameter and 300 mm height respectively.

When concrete is its plastic state, it is known as fresh concrete. Fresh concrete can be easily molded to a durable structural member. It can be prepared on the spot and may give a wide range of properties from easily available raw materials. Properties of Fresh Concrete. Workability. Temperature. Water Cement Ratio. Segregation. Bleeding

Concrete strengths may be increases without the need for further cement addition by maintaining some workability but at a lower water content While maintaining the same w/c ratio and workability, concrete can be made to a given strength as in the reference concrete at a lower cement content

International Research Journal of Advanced Engineering and Science ISSN (Online): 2455-9024 128 D. B. Eme and C. Nwaobakata, "Effect of coarse aggregate gradation on workability and flexural strength of cement concrete," International Research Journal of Advanced Engineering and Science, Volume 4, Issue 1, pp. 128-132, 2019. Effect of Coarse Aggregate Gradation on Workability

Apr 01,  · The improvement in strength of concrete with cement content at low volume fraction of aggregate is observed to be higher than those with higher aggregate volume fraction, i.e. when the cement content is increased from 250 to 450 kg/m 3, the compressive strength increases by 28 MPa in concrete with a CA/TA ratio of 35%, while this increase is

In the experiment of pervious concrete, slump value indicates effective binding .It has no reference to workability of pervious concrete. From the Table 4 we could infer the different slump values at different aggregate-cement ratios. As the A/C ratio increases due to lack of concentration of cement paste relative to aggregate slump value increases.

May 09,  · Factors affecting concrete workability: 1. Water-Cement ratio 2.Amount and type of Aggregate 3.Amount and type of Cement 4.Weather conditions 5.Temperature 6.Wind 7.Chemical Admixtures 8.Sand to Aggregate ratio. i. Water content or Water Cement Ratio. More the water cement ratio more will be workability of concrete.

aggregate gradation, and aggregate size and shape, cement quality, mixing time, mixing ratios, curing etc. Concrete must be both strong and workable, a careful balance of the cement to water ratio is required when making concrete. Fine aggregate are basically sands won from the land or the marine environment. Fine aggregates generally consist

Aggregates comprise as much as 60% to 80% of a typical concrete mix, so they must be properly selected to be durable, blended for optimum efficiency, and properly controlled to produce consistent concrete strength, workability, finishability, and durability (Photo 1). The ingredients in conventional concrete mixes usually fall within these

Abstract This paper examines the variation of workability and characteristic strength of laterized concrete (concrete containing laterite fine aggregate instead of sand) with different water/cement ratios and mix proportions. Four mixes of cement: lateritic soil: crushed granite were considered, namely 1:1:2, 1:1 1 2 :3, 1:2:4 and 1:3:6 . Two methods—slump and compacting factor tests were

More the water cement ratio more will be workability of concrete. Since by simply adding water the inter particle lubrication is increased. High water content results in a higher fluidity and greater workability. Increased water content also results in bleeding. another effect of increased water content can also be that

aggregates on the concrete blocks. They concluded that the slump values for the two types of crushed aggregates decreased moderately with water-cement ratio and concrete samples made with “vertically shafted” coarse aggregate having higher slump value than those with “impact crushed”. However, the

The range of water cement ratio between 0.40 and 0.45 has shown to produce the strongest concrete. Concrete Strength and workability affect by aggregate-cement ratio Concrete is formed by mixing mainly water, aggregates and some times admixtures. For a given cement and acceptable aggregates. The strength that may be developed by a workable is

However, water-cement ratio above 0.65 was observed to have a very significant reduction effect on the compressive strength of the lateritic concrete mixes. This is in contrast to the performance of the concrete mixes which shows consistent decrease of compressive strength in water-cement ratio. Also, the degrees of workability of both concrete

Concrete mix ratio of 1:3:3 - On mixing 1 part cement, 3 parts sand with 3 parts aggregate produces concrete with a compressive strength of 3000 psi. On mixing water with the three ingredients, a paste is formed that binds them together till the concrete mix gets hardened. The strength concrete is inversely proportional to the water/cement

Jul 25,  · C20 concrete would be considered a medium-strength concrete mix. Higher numbers indicate a stronger concrete. Increasing the Strength Adjusting the strength of concrete based on the ratio of sand to cement is easy to do. The closer you bring the ratio to an even one-to-one ratio of sand to cement, the stronger you will make the concrete.

Cement slurry also escapes through the joints of formwork resulting into the loss of cement from concrete. 02. The Size of Aggregates: Workability is mainly governed by the maximum size of aggregates.Water and paste require, will be not less if a chosen size of aggregates for concrete is bigger.

Hence the optimum percentage of flaky aggregate in the concrete is 20%. • By addition of admixture, the concrete with 20% of flaky aggregate also shown good improvement in strength and workability. References [1]. A.Abdullahi. M, The Effect of aggregate type on Compressive strength of concrete, International Journal of Civil and Structural

Apr 22,  · With fixing proper volume of fine aggregate in total aggregate volume, Design Mix Concretes attained more or less equal slump, flow, strength and durability properties with River Sand (45%), M-Sand (40%) and Crushed Stone Sand (36%) without changing cement content and free water cement ratio.

selecting aggregates for concrete. The compressive strength of concrete depends on the water to cement ratio, cement to aggregate ratio, degree of compaction, bond between aggregate and mortar, strength, shape and size of the aggregates (Rocco and Elice, ; Elice and Rocco, and Abdullahi, ).