The concrete slump test measures the consistency of fresh concrete before it sets. It is performed to check the workability of freshly made concrete, and therefore the ease with which concrete flows. It can also be used as an indicator of an improperly mixed batch. The test is popular due to the simplicity of apparatus used and simple procedure.

بیشتر

Q. What factors affect the mixing time? A. The importance of thorough mixing for the development of strength and uniformity throughout the batch has long been recognized. With a proper loading sequence, truck mixers should adequately mix the …

بیشتر

2.2. Selection of the Levels of Key Mix Design Factors. Selection of the levels of the three key mixture design factors, namely, cementitious materials content, water/cementitious materials ratio, and fine/total aggregate ratio, which mainly affect the quality of concrete will be made to ensure that enough experimental data are generated …

بیشتر

This is especially true during extreme weather conditions because various environmental factors can affect the concrete slab. Thus, the strength development of your concrete can be compromised. 3 Techniques for Efficient Concrete Curing. Many factors affect the rate at which water evaporates from freshly placed concrete.

بیشتر

The various factors affecting the changes in concrete strength can be studied by controlling each certain variable. Currently, conducting accelerated tests in the laboratory is the main method for studying the effect of a single factor on the strength of concrete. ... (1937 series) under the influence of different cement types, mix proportions ...

بیشتر

While the less amount of cement in concrete mix reduce the workability of concrete. 3. Water Content of Concrete (Water-Cement Ratio) The water-cement ratio is the most important factor which affects the workability of concrete. Generally, a water-cement ratio of 0.45 to 0.6 is used for good workable concrete mix (without the use of any admixture).

بیشتر

The various factors affecting the choice of concrete mix design are: 1. Compressive strength of concrete. Concrete compressive strength considered as the most important concrete property. It influences many other describable properties of the hardened concrete. The mean compressive strength (fcm) required at a specific age, usually 28 …

بیشتر

Concrete mix design is a particular job to achieve the desired concrete strength. Many problems can result due to improper mixing of concrete and affect the strength and durability. Bleeding of concrete is one such problem. Bleeding in fresh concrete refers to a process where fresh water in a mix is pushed upwards to the …

بیشتر

Factors affecting concrete mix design. Strength and durability of the concrete mix design are dependent upon the following factors: Grade designation: Concrete's strength is measured in N/mm2 when subject to test after curing in any curing medium. The choice of concrete grade depends on its usage. Choice of cement: …

بیشتر

What factors affect concrete compressive strength? Several factors affect the compressive strength of concrete, including: The quality of the raw materials in the mix ; The water-cement ratio; The type and grade of aggregate used; Generally, the more portland cement that is added to the mix, the higher the psi rating of the concrete.

بیشتر

Control of Concrete Mixtures, 13th edition, Portland Cement As-sociation, 1994. 2. Vance Dodson, Concrete Ad-mixtures, Van Nostrand Reinhold, New York, 1990 3. Factors Affecting Air En-t r a i n m e n t, Techletter DX80-1002, Grace Construction Prod-ucts Division. 4. W.L. Dolch, "Air Entraining Admixtures," Concrete Admix-tures Handbook ...

بیشتر

The three main factors that can cause fluctuations in the concrete slump are concrete temperature, the aggregates in the mix, and the mixing time for the load. Each one of these has the potential ...

بیشتر

Water/Cement/Aggregate Ratio. The ratio in which you add the different components of the concrete together is an incredibly key factor in creating strong or weak concrete. By adding more or less of just one …

بیشتر

The idea behind the limiting temperature of concrete is to avoid the cracking causes at different stages of its life span. It improves the durability of concrete. This is one of the factors affecting durability of concrete. The following issues could rise if the temperature is not controlled. Cracking of immature concrete

بیشتر

Factors affecting workability are ... The water content of controlled mix cannot be increased significantly, since it adversely affects the strength of concrete. Mix Proportion: Higher aggregate/cement ratio makes the concrete leaner. For such mixes, the cement paste that is available for lubrication between the aggregates will be lesser, per ...

بیشتر

The main factors that affect the failure of concrete structures are: Incorrect selection of materials. Errors in design calculation and detailing. Improper construction techniques and insufficient quality control and supervision. Chemical attacks on concrete structures. External mechanical factors.

بیشتر

1. Aggregate grading influences the mix proportions for a specified workability and water-cement ratio.
2. The relative proportions between coarse and fine aggregate in concrete mix influence concrete strength.
3. Well graded fine and coarse aggregate produce a dense concrete because of the achievem…

1. Aggregate grading influences the mix proportions for a specified workability and water-cement ratio.
2. The relative proportions between coarse and fine aggregate in concrete mix influence concrete strength.
3. Well graded fine and coarse aggregate produce a dense concrete because of the achievement of ultimate packing density.
4. If available aggregate, which obtained from natural source, does not confirm to the specified grading, the proportioning of two or more aggregate become essential.

See more

بیشتر

Many factors can affect the compressive strength of concrete, including the mix design, water-to-cement ratio, and curing conditions. Of these, the mix design is perhaps the most important. The mix design is a recipe that specifies the proportions of cement, aggregate, water, and other ingredients in the concrete.

بیشتر

1. Cement Content Quantity of cement used in concrete mix will also be a factor affecting durability of concrete. If cement content used is lower than the required, then water cement ratio becomes reduced and workability …

بیشتر

Abstract Concrete is a low-maintenance composite material that is …

بیشتر

Following are the factors that impact the slump of the concrete: Water cement ratio: The more the water-cement ratio, the more the slump. The water decreases the friction between filler aggregates. As a result, the ingredients get a slipping effect that results in more slump value.

بیشتر

However, efficient doesn't always mean super quick. A variety of factors …

بیشتر

The mixing of concrete constituent materials i.e. cement, water, aggregates and admixtures in specified proportions will produce a concrete of adequate strength. The mix design strength developed for a given type of cement is dependent on the following factors: Water/Cement Ratio. Cement Content. Relative proportion of fine and coarse aggregates.

بیشتر

Since the fineness increases the rate of hydration, it leads to an increase in the strength gain rate. Increase in the fineness improves the workability of concrete and also increases the setting time of the concrete. Higher …

بیشتر

Quality concrete must be assumed in any discussion on how various substances affect concrete. In general, achievement of adequate strength and sufficiently low permeability to withstand many exposures requires proper proportioning, placing, and curing. Fundamental principles and special techniques that improve the chemical resistance of ...

بیشتر

Two types of concrete mix designs are used which are ACI 211.1-91 (2002) Standard and British Standard (1997) in this paper. Several factors have been determined in this study to choose between ...

بیشتر

For a given workability an increase in the proportion of cement in a mix has little effect on …

بیشتر

Q. What factors affect the mixing time? A. The importance of thorough mixing for the development of strength and uniformity throughout the batch has long been recognized. With a proper loading sequence, truck mixers should adequately mix the concrete in 70 to 100 revolutions. If high-range water-reducing admixtures are added to the batch at the ...

بیشتر

Factors affecting concrete mix ratio. In order to create the perfect concrete mix for your project, consider the factors that can affect the mix ratio, such as the required strength of the concrete, the type and size of aggregate being used, and the climate and weather conditions at the time of mixing. Strength requirements will vary depending ...

بیشتر

Two other main factors affect the quality of concrete. These are density and curing time. How does the density of the concrete affect the final material? The denser the concrete, the more particles are interlocked and the stronger it will be. A dense concrete mix is shaken thoroughly in moulds, and more concrete is added to the space as the mix ...

بیشتر