With the rapid development of the national economy and the continuous improvement of people’s living standards, nowadays the society is more and more concerned about the engineering quality of water conservancy projects, and whether cracks appear in the concrete in water conservancy construction is able to directly reflect the quality of water conservancy projects.
Therefore, in the construction of water conservancy projects, the main causes of concrete cracks should be analyzed, and to find a suitable solution to ensure the safety of people’s lives and property.
1 The main construction characteristics of the water conservancy project
Water conservancy project construction has a long construction period, the construction process is more complex and construction scale and other construction characteristics. These construction characteristics are able to make the construction of water conservancy projects in the construction of certain quality problems, coupled with the construction of water conservancy projects are susceptible to natural environmental factors, resulting in concrete cracking problems have become a prominent problem in water conservancy construction.
Water conservancy project is an important national basic construction project, its purpose is to ensure the safety of people’s lives and property from flooding, so that the water conservancy project has the significant characteristics of large scale and long construction cycle; secondly, in the process of construction, due to the special nature of water conservancy construction, easy to be affected by the natural environment, which led to the construction process of water conservancy construction is very complex. , these natural factors include the construction site complex terrain, etc., these factors will have a certain impact on the quality of water conservancy projects, endangering the safety of life and property of the construction workers.
Therefore, in the process of construction, the construction personnel should be based on the characteristics of water conservancy construction, the construction process is strictly controlled, the quality of the problems arising from careful analysis to find solutions, and the development of relevant construction standards to prevent the recurrence of such engineering quality problems.
2 The main causes of concrete cracks in water conservancy projects
2.1 As the main solidification process of concrete inside and outside the temperature difference leads to the emergence of concrete cracks
In today’s water conservancy project construction, the general use of concrete structure, after the completion of concrete pouring, in the subsequent process of concrete will produce the phenomenon of heat of hydration, this phenomenon tends to make the concrete internal temperature difference, such temperature difference can cause concrete thermal expansion and contraction, which leads to the appearance of concrete cracks.
The reasons for the phenomenon of temperature difference inside concrete are generally the following.
The first is because in the process of concrete pouring construction of water conservancy projects, there is not enough cooling conditions, which leads to a higher temperature inside the concrete, in the process of concrete solidification, due to the evaporation of water in it, resulting in a large temperature difference between inside and outside the concrete, thus producing concrete cracks.
Another situation is due to the lower temperature inside the concrete during the construction of water conservancy projects in winter, resulting in the emergence of osmotic pressure, which will also cause concrete cracking.
The last reason is because of the low temperature at the construction site, during the process of concrete solidification, the moisture inside the concrete is frozen, which makes the internal volume of the concrete expand rapidly, and this can also produce concrete cracks.
2.2 Concrete cracks due to the imbalance of external forces
Hydraulic projects generally have a large scale, which leads to the construction process, the construction personnel can not well grasp the force situation of the concrete, resulting in the surface or side of the concrete due to uneven force, resulting in the appearance of concrete cracks. This uneven situation in the hand is often due to the complexity of the construction technology and conditions of water conservancy projects, can not have a detailed understanding of the structural characteristics of water conservancy projects, or because the construction personnel in the construction of the concrete materials before the specific force to make a detailed analysis of the test, resulting in the process of construction caused by the uneven force situation of concrete.
This situation generally occurs in the construction of dams in water conservancy projects, construction personnel to strengthen the upper layer of the dams in water conservancy projects, due to the lower layer of the dike force does not have a specific grasp of the situation, resulting in the lower layer of the dike force overweight, resulting in cracks in the concrete; another situation is the uneven force on the side of the concrete resulting in cracks in the concrete, water conservancy project dams in the interception of water flow In the process of intercepting the water flow, the flow of water has a single nature, so that the side of the dam is subjected to a large impact, resulting in uneven force on both sides of the dam, which is also prone to concrete cracks.
2.3 The complexity of the construction site of water conservancy projects leads to concrete cracks
The construction scale of water conservancy projects is large, so when the water conservancy construction is carried out, the selected construction site is generally far away from the city, so that the construction site is relatively complex because of the lack of artificial development, which has a certain impact on the construction of water conservancy projects, and the construction personnel can not make a specific examination of the specific construction environment of the construction site, which leads to the construction process can not pass These topographic data and water conservancy projects for reasonable construction, these topographic reasons mainly include the following aspects.
First is the construction site is richer in groundwater resources, in the season of higher rainfall, the circulation of these groundwater will accelerate, thus causing greater impact on the building structure of the water conservancy project, in the long run, there will be concrete cracks;.
Secondly, because the soil structure of the foundation of the water conservancy project, some water conservancy building land structure is relatively loose, which causes the construction process can not be well on the foundation of the water conservancy building for adequate reinforcement, which leads to the phenomenon of subsidence of the water conservancy building, this phenomenon can cause the uneven force of the water conservancy project building structure, which leads to the generation of concrete cracks.
3 water conservancy project in the concrete crack prevention measures
3.1 Ensure the quality of raw materials of concrete
The quality of raw materials of concrete directly determines the construction quality of water conservancy projects, so the construction unit in the purchase of concrete materials, must strictly grasp the quality of concrete, for the structural characteristics of water conservancy buildings, a reasonable proportion of concrete, after the completion of the proportion, for the force of various parts of the water conservancy project, to the proportion of the concrete for the force test, to ensure that the performance of concrete To meet the construction requirements of the water conservancy project.
Before the construction of the water conservancy project, the construction personnel should strictly check the construction materials and equipment, and select the appropriate construction materials and equipment according to the construction plan to ensure the smooth implementation of the entire construction project .
3.2 Control the temperature during concrete placement and solidification
The temperature difference between the inside and outside of concrete is the main cause of concrete cracks, so the construction personnel should strictly control the temperature therein, and this control of concrete temperature is generally reflected in the following aspects.
Firstly, in the selection of raw materials for concrete, those cements with less heat should be selected as far as possible.
Secondly, according to the construction season, in the construction process, control the temperature of concrete, in the summer when the construction of water conservancy projects, the construction personnel should cool down the interior of the concrete to reduce the occurrence of temperature differences due to water evaporation, in the process of concrete pouring, if the construction site temperature is high, the construction personnel can add an appropriate amount of ice water in it to achieve the control of The purpose of temperature; choose the appropriate pouring process, in the process of concrete pouring, you can choose the layered pouring process, can increase the contact area of the concrete, speed up the heat dissipation, you can also add water pipes inside the concrete, in the case of high temperature, you can add ice water to reduce the internal temperature of the concrete.
3.3 solve the external imbalance in the water conservancy project
Before the construction of the water conservancy project, the construction personnel should make a detailed analysis of the force situation of each part of the water conservancy building, especially for the dam part of the water conservancy building, to consider the speed and impact of the intercepted water, in addition to the concrete load-bearing capacity of the test, to ensure the balance of forces in the structure of the water conservancy building in all parts .
In the construction of water conservancy projects, in order to ensure the quality of water conservancy projects, the construction personnel should analyze the main causes of concrete cracks in the construction process, so as to control the main factors to reduce the concrete cracks, so as to improve the quality of the project and ensure the safety of people’s lives and property.