1, cement concrete paving
At present, high-grade cement concrete pavement construction is carried out by sliding mode paving method. The concrete pavement paving is a difficult and technically demanding process. We only prepare from the paving The rational use of paving machine, paving after maintenance and other aspects are often overlooked in several aspects of analysis.
1.1 Preparation before paving
There are a lot of preparations for concrete paving, and we mainly emphasize the discharge process before sprinkling the paving.
(1) before the spread of water is a seemingly simple process, often not the construction staff attention, but if the sprinkler treatment will seriously affect the quality of the road.
Sprinkler should be based on the grassroots material, air temperature, humidity, wind speed and many other factors to determine the amount of water, that is, to ensure that the paving concrete before the grass-roots wet, and as far as possible evenly spread, especially in the grass is not flat to prohibit the phenomenon of water. From the current construction site, in most cases is the lack of water, because the grassroots dry, pavement after the concrete pavement at the bottom of a large number of small cracks, and some small cracks and concrete shrinkage of the stress generated by the overlap after the entire concrete pavement cracks increase.
(2) dump truck unloading is often not be attention to the process, often in the construction of the paver before the stacking of too much to make the paver difficult to walk, and sometimes too much fabric to suppress the amount of concrete in the box, Thickness is not guaranteed. This phenomenon of concrete suddenly before the paver will seriously affect the smoothness of concrete pavement. In the construction process, most of the construction workers rigidly spaced a certain distance from the unloading of a car material, while ignoring the uneven formation of the grassroots changes, which we are in the objective is ubiquitous. China's current construction level is not very high, the road surface elevation and unevenness is inconsistent, increasing the difficulty of concrete pavement construction. In the actual construction, I can flash the base surface and the surface layer of the benchmark line to determine the actual discharge of concrete discharge, which will avoid the problem of uneven discharge.
1.2 Rational use of concrete paver
(1) The determination of the spacing of the vibrator appears to be simple, but it will have a direct effect on the density of the concrete. The spacing of the vibrators is generally adjusted at the height of the installation of the manufacturer, and it is this, which means that the operator neglects the repositioning of the vibrator in use because of the gradation of the different concrete, the ease, slump And the density of the pavement, the spacing of the vibrators should be adjusted as appropriate. In particular, the distance between the two sides of the vibrator should be adjusted to prevent collapsing. In addition, the hydraulic vibrator with the use of time lengthening, vibration capacity has declined, according to the actual situation to make adjustments.
(2) Many paver side of the template is raised and lowered through the hydraulic cylinder. In actual use, the edge of the template can not be too large with the grass-roots spacing to prevent serious leakage of pulp, due to this requirement, paving walking process with the grassroots changes, the edge of the template will be directly contact with the grass, Seriously affected the molding die on the concrete extrusion in the type, the collapse of serious.
(3) from the current domestic construction unit point of view, most of the unit paving capacity is far greater than the mixing of production capacity. This is mainly due to the general paver maximum paving capacity are greater than 5003 / h, while the concrete production capacity is only 100-2003 / h, some units less productive capacity, emphasizing this is mainly to illustrate the paving machine paving speed There is no need to open very quickly, unilateral speed and can not improve the construction progress.
In the construction of the paving speed if the control in the 1-2m / min or so, will make the paver running smoothly, smooth road surface, continuous paving possible. And if the concrete paving speed will cause paving stops, not only to start each time the equipment wear greatly increased, and each time the downtime of the downtime is inevitable, resulting in poor road surface roughness.
1.3 Maintenance after paving
After the concrete pavement paving the routine maintenance process, can not be discussed here, we only analyze the time of the slit, in some construction specifications listed in the sewing machine began to cut the schedule. Here is the time that the slit time begins when the concrete is smoothed.
It is not difficult to see that this table only lists the effects of temperature on the cutting time, but the actual construction of concrete pavement after the strength is not only the temperature of a condition, as well as humidity, wind speed, road thickness and the content of concrete additives and other important factors The According to the actual situation to determine the slit time, if you do not consider the wind speed, usually the slit time is too late, the higher the strength of the concrete cutting speed, cutting machine and Blade damage is high.