What Are The Problems With Grout?

What are the problems with Grout?
One, hemp
    Phenomenon: the phenomenon of local surface filling Grout and many small pits, pitting, forming rough surface, but no steel exposed phenomenon.
    Causes
    1. The surface of the template rough or sticky cement slag and other debris is not clean, mold removal when the surface is destroyed;
    2. The template is not wet or wet water is not enough, the surface of the component Grout moisture is sucked, so that there is too much waterlogging grout;
    3. template patchwork lax, local leakage pulp;
    4. Template release agent brushing uneven, or local leakage brush or failure, Grout surface and template bonding caused by Ma face;
    5. Grout vibrate is not real, the bubble is not discharged, stopped at the surface of the template to form pitting.
    Prevention
    1. Template surface clean-up, not sticky with dry hard cement mortar and other debris; watering Grout, the template should be fully wet watering; template gap, the application of linoleum paper, putty and other blocked; template release agent should use long- Brushing evenly, not leakage brush; Grout should be evenly vibrated evenly, until the bubble so far;
    2. The surface of the paint, do not deal with the surface phenomenon without paint, should be wiped in the pavement full watering, the available 1: 2 or 1: 2.5 cement mortar, the linen wiping pressure light.
    Second, the surface is not smooth
    Phenomenon: Grout surface uneven, or thin plate thickness, uneven surface.
    Causes
    1. Grout after pouring, the surface only with shovels, not trowel leveling pressure light, resulting in rough surface;
    2. The template is not supported on the hard soil layer, or the bearing surface is insufficient, or support loosening, soaking the water, resulting in the new watering Grout early maintenance occurs uneven sinking;
    3. Grout did not reach a certain strength, the man operation or transport material, so that the surface phenomenon of depression or imprinting.
The determinants of the strength of high-strength non-shrinkage Grout are mainly the mixing ratio, water-cement ratio, aggregate, admixture, density and later maintenance. The following is a detailed overview:
1, with the ratio
Through a reasonable mix design, so that the strength of Grout higher.
2, water-cement ratio
The compressive strength of high-strength non-shrinkage Grout is proportional to the strength of Grout cement. According to the formula, when the water-cement ratio is equal, the strength of high-strength grade cement is much higher than that of low-strength grade cement. In addition, the water-cement ratio is also proportional to the strength of the Grout, therefore, when the water-cement ratio is constant, attempt to increase the amount of cement to increase the strength of the strength of the soil is wrong, this time only increase Grout workability, Grout shrinkage and deformation.
In summary, the main factors that affect the compressive strength of high-strength non-shrinkage Grout are cement strength and water-cement ratio. To control the quality of Grout, the most important thing is to control the water and cement ratio of cement and Grout. In addition, the impact of Grout strength there are other factors can not be ignored.
3, aggregate
Aggregate has a certain effect on the strength of high-strength non-shrinkage Grout, when the stone strength is equal, the gravel surface than the pebble surface roughness, it is stronger than the cement mortar cobblestone than pebble, when the water-cement ratio is equal or the same, The Grout strength of the two materials is stronger than that of the pebbles. The effect of fine aggregate on the strength of Grout is less than that of coarse aggregate, so the quality of sand is not reflected in the Grout formula, but the quality of sand has a certain influence on the quality of Grout. Therefore, the quality of gravel must meet the requirements of gravel quality standards for gravel. Due to the relatively large change in the quality of gravel at the construction site, the site construction personnel must ensure the quality requirements of sand and gravel, and adjust the water-cement ratio according to the sand moisture content in the field to ensure the Grout ratio. Confused.