Abstract: Some quality problems often occur in road construction, which affect the later construction and use. This paper will discuss the quality problems existing in road construction, and analyze the countermeasures, so as to make suggestions for improving the quality and level of road construction and promote the improvement of road construction technology.

Keywords: road construction; Quality; Problems; solve

In the process of highway construction, the construction is carried out in the natural environment, facing the influence of environment, geology, hydrology, climate and other aspects, which leads to the subgrade stability being damaged to varying degrees in the process of highway construction. In road construction, if the quality is not strictly controlled, the pavement will collapse or be damaged in the later period, which will affect the service effect and life of the road. To ensure the quality of road construction, it is necessary to educate, supervise and manage the construction site, construction skills, construction technology and construction personnel in many aspects, improve relevant rules and regulations, ensure the quality and quantity of each construction link, ensure the road construction quality to meet the standard and improve the road use efficiency.

Main quality problems in highway construction.

1. 1 lime soil construction quality problems

Lime soil is a material used to improve the compressive strength of roads in road construction, because lime soil has high compressive strength and good plasticity, and its manufacturing process is relatively easy. In the process of use, the quality of lime-soil construction will have the following problems: First, the surface peeling. This problem is mainly due to the unreasonable ratio of lime and water in the production of lime soil, which is not strictly controlled, and it is easy to peel after being crushed by large machinery in the later stage. Second, crack. This problem is also caused in the production process, mainly because there is no scientific equilibrium moisture content, and cracks will appear after thermal expansion and cold contraction. Third, the strength is poor. The strength of lime soil is influenced by the mixing time of materials and external conditions such as weather and environment. If it is not detected and controlled in time, the strength of lime soil will become worse. Fourth, the density is not enough. In the actual road compaction machinery construction, if the compressive force of the pavement is not well grasped, it will lead to insufficient compaction of lime soil.

1.2 quality problems of asphalt pavement

Asphalt is the material used to pave the road. Asphalt can make the pavement waterproof and compressive, and it is very flat, clean and durable. It is the surface material used in many pavements at present. The quality problem of asphalt layer is also a common quality problem in road construction, which is manifested as follows: First, transverse cracks. This is a load-type crack, and the inducement comes from external force. Due to the wheel load, the semi-rigid base produces tension. If the tension exceeds the load at the bottom, the material will crack. If the wheel load acts repeatedly, the cracking degree will increase and spread to the asphalt surface, resulting in transverse cracks. Second, there are a lot of cracks. This is a non-load crack, which is common in winter. When the temperature drops, the material contracts due to thermal expansion and cold contraction. If the tensile force of the middle layer of the material exceeds the tensile strength of the mixture, cracks will appear in the asphalt layer. Third, the washboard problem. This problem is mainly due to the poor thermal stability of asphalt mixture, and the moving ripple along the driving direction is caused by external force (driving).

1.3 quality problems of heavy oil or permeable oil

Adhesive layer oil or permeable layer oil is a method of spraying liquid petroleum asphalt or kerosene asphalt and emulsified asphalt on subgrade to form permeable layer. In this construction process, it is often because the holes of oil spreading equipment are not evenly opened or the equipment is lifted high, which will lead to uneven oil under the influence of external weather and environment.

1.4 kerb quality problem

The boundary stones at the edge of the sidewalk become kerbs to isolate them from other structural areas. Common kerb construction quality problems are as follows: First, it is not firmly placed. This is because the kerb groove is wide, and the compactness of backfill soil and bottom groove is not up to standard. Second, kerbs are squeezed. This is because the unreasonable operation of the roller in the rolling construction process leads to its rigidity theory rolling over the kerb, which causes the kerb to be damaged. Third, place it at will. When placing kerbs, there are no standards and specifications for the gaps in the middle, so they are placed at will. Fourth, kerb treatment. The kerb was not treated in time after being laid on the asphalt surface, and the slurry at the bottom was not treated in time.

2. Solutions to quality problems in road construction

2. 1 lime soil construction quality solution

First, the solution to the peeling problem: If the peeling height is higher than the design standard, it should be treated by fine scraping; if it is lower than the design standard, it should be treated according to the actual situation. When the second skin appears, it should be removed in time before laying the oil layer to prevent the washboard phenomenon. Second, the solution to the cracking problem: the material selection should be strict, and the sample test should be carried out first. The plasticity index should be in the middle range. If it is too high, the water content will be sensitive and cracked, and the degree will be enhanced. If it is too low, the strength of the material will be poor. Third, the solution to the problem of poor material strength: because soil quality is an innate condition, to improve the strength of materials can only be achieved by controlling the proportion of other materials. For example, for sand maps with low plasticity index, the stability and strength can be improved by using cement or increasing the amount of ash. The soil with high plasticity index can be stabilized by sanding or secondary mixing. Fourth, the degree of compaction is not enough. Solution: If the soil quality changes, it should be detected in time and compacted after reaching the standard. Before compaction, soil moisture should be tested to ensure that it meets the standards. When spreading lime, the quantity and uniformity should be controlled to ensure the compaction quality.

2.2 asphalt pavement quality problem solution

1. transverse cracks: glass fiber grating can be placed between asphalt surface course and semi-rigid base course to relieve or bear external pressure and reduce cracking problems. Or by adding fiber materials to asphalt materials to increase tensile strength, so as to achieve the purpose of reducing external pressure. Second, there are a lot of cracks. The problem of massive cracks can also refer to the solution of transverse cracks to slow down the tension problem caused by temperature difference, thus reducing cracks. Third, the washboard problem. Placing grids between the surface layers or at the top of the base layer can make the rubber in the material form a firm state without moving, improve the bearing capacity of concrete and avoid the influence of external forces such as driving.

2.3 Solutions to quality problems of heavy oil or permeable oil

Check oil laying equipment and construction conditions to ensure smooth hole laying and control construction standards. Reasonable control of construction procedures to ensure that there is no problem of intermittent construction.

2.4 kerb quality problem solving method

When placing, the gap width and related standards should be well controlled, and the verticality should be ensured when it is close to the side wall of the oil surface, and the bottom should be rammed flat; After filling, the compacted and backfilled materials shall be treated; In the design stage, considering the horizontal mud at the bottom of the kerb, the treatment scheme is formulated; After the oil surface is paved, we must pay attention to the timely detection and adjustment of kerbs to ensure that their quality meets the standards.

3. Conclusion

The quality of highway construction is the core of the whole highway construction project. For common problems such as materials, paving, construction technology and equipment, supervision and inspection should be strengthened to improve construction skills and level. In construction management, we should not only establish the idea of quality first, but also achieve strong supervision and management. Common construction quality problems should be predicted and solutions should be found in time. The solution should conform to the construction standards and the actual situation, so as to comprehensively improve the quality of road construction and ensure the later use efficiency and safety of the road.

;