Many friends have a vague and often confused understanding of concrete and mortar. Today, let’s explore the essence and difference between the two in detail.
The difference between mortar and concrete:
Cement mortar is a mixture of cement, sand and water. It has no aggregate and cannot form a strong skeleton and is difficult to withstand strong loads. In construction projects, cement mortar is used for foundation and wall masonry, as a binder for block masonry materials, such as rubble and red brick. And also cement mortar is used for indoor and outdoor plastering Ash.
Concrete is a general term for engineering composite materials in which aggregates are cemented into a whole by cementitious materials. Ordinary concrete is an artificial stone that is hardened by mixing cement, coarse aggregate (crushed stone or pebble), fine aggregate (sand), admixture and water.
Concrete has the characteristics of workability, high strength, deformability and durability.
Compared with the two, concrete has much greater bearing capacity and durability. Concrete mixed with a large amount of mortar will affect the bearing cage capacity of the concrete structure, destroy the safety performance of the structure, and also make the concrete poor in homogeneity, resulting in inconsistent shrinkage of various parts of the concrete. And it is easy to produce concrete shrinkage cracks, reducing the concrete impermeability and durability of frost resistance .
To product and convey concrete or mortar is not an easy job on construction sites when the required amount is especially large. So you need special tools to fulfill the work. Here are some machines recommended for various needs of concrete materials and mortar mixture, including pump trailer, boom pump, and mixer pump machines, etc.
Mortar properties
1. The workability of freshly mixed mortar
The workability of mortar refers to the mortar ability that can easily spread into a uniform and continuous thin layer on the surface of masonry and other surfaces, and is closely bonded to the base layer. Including two aspects of fluidity and water retention.
(1) Liquidity
The factors affecting the fluidity of mortar mainly include the type and amount of cementitious materials, the amount of water, and the type, particle shape, thickness and gradation of fine aggregates.
In addition, it is also related to the variety and dosage of mixed materials and additives.
Usually, the substrate is a porous water-absorbing material or construction job is under dry and hot conditions, a mortar with high fluidity should be selected. On the contrary, if the substrate absorbs less water, or the construction is under wet and cold conditions, the mortar with low fluidity should be selected.
(2) Water retention
Water retention refers to the ability of the mortar to retain water. The mortar with poor water retention will cause bleeding and slurries during use, which will make the mortar and the substrate not firmly bonded.And due to the loss of water, the normal bonding and hardening of the mortar will be affected. The strength of the mortar will be reduced.
1. The main factors affecting the water retention of mortar are the type and amount of cementitious materials, the type, fineness and water consumption of sand. Mixing powdered mixed materials such as lime paste and fly ash into the mortar can improve the water retention of the mortar.
2.Strength of hardened mortar
The factors that affect the strength of mortar are: when the quality of raw materials is constant, the strength of mortar mainly depends on the grade of cement and the amount of cement.
In addition, mortar strength is also affected by sand, admixture, mixed materials and masonry and maintenance conditions.
When the content of mud and other impurities in the sand is large, the strength of the mortar is also affected.
Properties of Concrete
1. Workability refers to the convenience of the operation of various construction procedures in the concrete mixture under certain construction conditions, so as to ensure the performance of uniform and dense concrete. Workability is a comprehensive technical index, including three main aspects: fluidity (consistency), cohesion and water retention.
2. Strength is the main mechanical property of concrete after hardening, which reflects the quantitative ability of concrete to resist load. Concrete strength includes compressive, tensile, shear, flexural, flexural and grip strengths. Among them, the compressive strength is the largest and the tensile strength is the smallest.
3. The deformation of concrete includes deformation under non-load action and deformation under load action. The deformation under non-loading action includes chemical shrinkage, wet and dry deformation and temperature deformation. Too much cement can easily cause chemical shrinkage inside the concrete and cause fine cracks.
4. Concrete durability refers to the ability of concrete to resist various damage factors under actual use conditions and maintain the strength and appearance integrity for a long time. Including the frost resistance, impermeability, corrosion resistance and carbonation resistance of concrete, etc.