What are the factors affecting permeability of concrete?
The major factors affecting permeability are as follows:
- Water/ cement ratio.
- Compaction and curing.
- Properties of cement.
- Aggregate.
- Absorption and homogeneity of concrete.
- Use of admixtures.
- Age of concrete.
What is the permeability of concrete?
Permeability is a measure of the amount of water, air, and other substances that can enter the concrete matrix. Concrete contains pores that can allow these substances to enter or depart.
Which of these factors affect the porosity and permeability of concrete?
Previous studies show that gradation, particle size of aggregate, and mass ratio of aggregate to cement are the primary factors affecting porosity, permeability and compressive strength of PCPC. Water cement ratio has a minor effect on properties of PCPC [12] .
What are the factors affecting concrete?
Factors Affecting Strength of Concrete
- Quality of Raw Materials.
- Water / Cement Ratio.
- Coarse / fine aggregate ratio.
- Aggregate / Cement Ratio.
- Age of concrete.
- Compaction of concrete.
- Temperature.
- Relative humidity.
What factors affect permeability?
Factors affecting Soil Permeability
- Factors affecting permeability include Particle size, Void ratio, Permeant, Shape of particles, Degree of saturation, soil fabric, Impurities in water and Adsorbed cation on clay mineral surface.
- Permeability is the ease with which the water can flow through soil.
What reduced permeability of concrete?
Generally, the higher the percentage of slag cement in a concrete mixture, the lower the permeability of the concrete. Concrete with lower permeability can generally be achieved by substituting between 25 to 65 percent slag cement for portland cement.
What is mean by permeability of concrete What are the factors affecting permeability of concrete?
Permeability of concrete is defined as the property that controls the rate of flow of fluids into a porous solid. There are several factors which influence the durability such as water to cement ratio, concrete compaction, concrete curing, and age of concrete.
What is the main factor that determines the strength of concrete?
The ratio of the weight of water to the weight of cement is called Water/Cement ratio. It is the most important factor for gaining the strength of concrete. The lower w/c ratio leads the higher strength of concrete. Generally, the water/cement ratio of 0.45 to 0.60 is used.
Which of the following factors influence the durability of concrete?
Permeability: It is considered the most important factor for durability. It can be noticed that higher permeability is usually caused by higher porosity. Therefore, a proper curing, sufficient cement, proper compaction and suitable concrete cover could provide a low permeability concrete.
What is permeability discuss the factors influence permeability?
The factors that affect the coefficient of permeability for a given soil are particle size distribu- tion (grading curve), void ratio, level of saturation, soil structure, and soil imperfections or discontinu- ities [1, 2, 3, 4]. The coefficient of permeability increases significantly with increase in the void ratio.
What are the two main factors that determine membrane permeability?
The permeability of a membrane is affected by temperature, the types of solutes present and the level of cell hydration. Increasing temperature makes the membrane more unstable and very fluid.
How does permeability affect on the durability of concrete?
Concrete permeability influences durability because it controls the rate that moisture, which could contain an aggressive chemical, enters concrete and the movement of water. Decreasing the w/c ratio also increases concrete strength which further improves its resistance to cracking [16].
Hence, concrete would be permeable when free water leaves the pores due to evaporation or any other reason. Fig.1 explains the relationship between water to cement ratio and concrete permeability. Typically, at a water cement ratio of around 0.4, permeability is practically nil.
What factors affect the permeability of a porous material?
It largely depends on the size of pores, connectivity of pores, and how tortuous the path is for the permeating fluid. The pores relevant to permeability are those with a minimum diameter of 120 or 160nm, and they have to be connected. Isolated pores, pores filled with water, and pores with a narrow entrance and irrelevant to permeability.
What are isolated pores in concrete?
Isolated pores, pores filled with water, and pores with a narrow entrance and irrelevant to permeability. There are several factors which influence the durability such as water to cement ratio, concrete compaction, concrete curing, and age of concrete.
What are the factors that affect the durability of concrete?
There are several factors which influence the durability such as water to cement ratio, concrete compaction, concrete curing, and age of concrete. So, such factors shall be taken into consideration during mix design and construction of concrete structure. 1. Water to Cement ratio
