Construction materials thesis 3000 words

With the continuous development of social economy, China's construction industry has been rapid development, in the process of continuous development needs to be strict control of the quality of construction materials. The following is what I have collected and organized for you about the construction materials essay 3000 words, welcome to read reference!

Construction materials essay 3000 words 1

An introduction to the quality of construction materials testing problems and countermeasures

Abstract: As the basis of construction projects, the quality of materials directly determines the safety and durability of the building, but also an important guarantee of personal and property safety of building users. Therefore, the relevant departments must pay full attention to the detection of material quality, to eliminate the use of poor quality building materials due to the use of building construction in the construction of ? Tofu dregs project? This paper starts from the necessity of building materials quality testing, combined with the author's practical experience, analyzes the current problems in the quality testing of building materials, and puts forward specific countermeasures to improve the level of quality testing of building materials.

Keywords: construction materials; quality testing; problems; countermeasures

1. The necessity of quality testing of construction materials

With the sustained and rapid development of China's economic construction, the level of design and construction of building projects has made great progress, and provides the necessary technical support for the realization of the economic and social value of China's various construction projects. As the foundation of the construction project, the construction material refers to the general name of all the materials used in the construction project, mainly including the main body of the building construction materials and decorative materials of two categories. The quality of these materials directly determines the safety and durability of the building, and is also an important guarantee for the safety of personal and property of building users. However, from the statistical data, the current unscrupulous units and individuals in the construction of building construction using poor quality building materials, built ? Tofu dregs project? cases still occur from time to time throughout the country, seriously detrimental to the stable development of China's construction industry. In this context, the quality of construction materials testing has become a key link to ensure the quality of construction projects, and must be caused by the relevant units of great importance.

2. Currently different building materials quality testing in the existence of specific problems

The current building materials testing in the quality of the problem mainly stems from the testing workers of China's current test standards and testing procedures lack of in-depth understanding of the characteristics of a variety of building materials and inadequate knowledge of the properties, failed to grasp the scientific sampling methods, test methods and evaluation, and sometimes even out of interest, to make unrealistic decisions. Sometimes even out of interest, make unrealistic test reports, violating the detection of accurate, scientific and fair work principles. And different types of construction materials in the detection of common problems are as follows:

2.1. steel testing

Steel testing is mainly divided into the detection of reinforcing bars and welding specimen testing. As a result of construction projects in the amount of rebar, more varieties, complex channels of purchase, coupled with construction site restrictions and other reasons, there are often chaotic management problems, it is difficult to the same factory, the same specification, the same furnace can number, and the same delivery state of the rebar batch testing. Although the standard clearly requires sampling from the same batch of different bundles should be randomly drawn 2 and interceptor end 0.5m2 section, respectively, for cold bending and tensile testing, but some construction units in order to reduce the use of sized rebar from the waste pile to find out the test of steel, so that the test results lack of representativeness. In the welding specimen, some units in the construction of the importance of neglecting the welding preparation work, not according to the different welding form to develop a reasonable sampling frequency, or not from the finished product sampling and directly do the simulation specimen, so that the results are distorted.

2.2. Cement testing

Some units due to the unstable purchase channels, cement varieties, or for convenience, not the same manufacturer, the same species, the same strength, the same batch of cement and the successive entry of the cement as a sampling unit, so that the sampling has lost the representativeness. Due to the long time of the stability test of cement, many construction units to grab the schedule, are in the stability test results have not been obtained when the use of cement, once the test results show that the quality of cement materials, will give the project caused by the greater loss of time and cost; some of the factory more than 3 months of the cement has not been timely re-inspection, coupled with poor management of the site pile, resulting in the strength of the damaged and then still use it as usual! Some cement which has been delivered for more than 3 months is not re-inspected in time, coupled with poor management of site stacking, resulting in its strength being damaged and still used as usual. A lot of bagged cement is not random weight sampling, resulting in a serious phenomenon of cement weight over the difference, and the negative error value of the cement will not only have an impact on the cost control of construction projects, but also not conducive to improving the accuracy of the construction site proportioning, easy to lead to the reduction of strength of the components or masonry mortar.

2.3. Other building materials testing

Other common construction materials testing problems include: field sampling of coarse sand instead of fine sand, and did not adjust the moisture content of sand; grading of crushed stone grading test is not in line with the specification requirements; brick sampling is only good quality to send the inspection of the surface of the phenomenon of the lack of angularity do not pay attention to, and compressive strength test is not rigorous, can not ensure its performance. Ensure its performance.

3. Measures to improve the quality of construction materials testing level

To improve the quality of construction materials testing level, in addition to the above problems must be strictly in accordance with the national and industry testing standards for the operation of the following key aspects of the key control:

3.1 Control of ambient temperature and humidity

Temperature and humidity have a greater impact on the performance of construction materials. The performance of building materials have a greater impact, such as elastomer modified bitumen waterproofing membrane (SBS) and other waterproofing materials required to do tensile test room temperature must be controlled at (23?2) ℃, the data show that if the test is carried out in the environment at 28 ℃, the average value of the tensile strength of the specimen than the standard temperature environment is lower than the average value of the standard temperature of 2.85%, and in the environment of 18 ℃, the average value of the tensile strength of its tensile strength than the standard value is higher than the average value of 3.55%. . It can be seen that the temperature and humidity must be controlled within the specified range to ensure the correct reliability of the detection and test data.

3.2 Detection of a reasonable determination of the project

Construction site used in the construction of a wide variety of materials, into the detection, testing materials project to comply with the relevant provisions of the state, the industry and the local construction authorities. For example, the testing of the main material cement, according to the batch test its stability, strength, setting time and the fineness of the cement, concrete with coarse aggregate should be determined in accordance with the routine particle grading, density, mud content and mud content, acicular particles content and other test items. If used for concrete greater than or equal to C35 grade, it is necessary to do the crushing index, the newly adopted loose texture of the aggregate should also do the solidity test, active aggregate to do the activity test.

3.3 Sampling specification

Sampling and sampling has a strong technical, need to inspectors with a high degree of responsibility and skillful operation skills, and the use of scientific and reasonable sampling methods. Different materials have different sampling requirements, so the program should be designed before sampling. The representativeness of sampling depends on the arrangement and number of sampling points, and the arrangement of sampling points should be based on randomization. Take bagged cement as an example, should be the manufacturer, production time, grade, factory number of cement as a test batch of the same, and the total amount shall not exceed 200t. Sampling point shall not be less than 20, the total sample mass shall not be less than 12kg. such as a number of factory cement ****1000t, the batch of cement needs to be divided into two batches of test, each batch of sampling interval of 500/20=25(t). Each batch sampling interval is 500/20=25(t). In the beginning of the number of the first 25t of cement in any bag as the first sampling point, take the first sample, followed by 25t as the interval, in turn, the remaining 19 samples, the weight of each sample should be ?12/20 = 0.6 (kg).

3.4. Scientific processing of test data

As the test data of construction materials may sometimes have a high degree of dispersion, it is necessary to make reasonable trade-offs for certain results. To the cement sand flexural strength test, for example, if the three strength values appear & gt; average? 10% of the results, that is, the data should be deleted, and the average of the rest of the data to re-calculate, evaluation. Calculation of the results of the revision should be carried out in accordance with GB/T8107-87 "numerical revision rules". In addition, the operator's proficiency of the difference and the homogeneity of the material, equipment and instruments, environmental conditions and other factors, will make the detection, test results produce error, error beyond the permissible range must be retested. The same material, the same sample in different test equipment in the test results obtained by the error is called reproducibility error. Tests are generally more homogeneous materials such as steel samples are divided into two, one to the local quality inspection agency, another to stay in this unit, analyze and compare the test results of the two test units, if the relative error is large, you should find out the reasons and be improved.

4. Conclusion

Detection link is to ensure the quality of various materials in the project, to improve the safety and durability of the building is an important guarantee, must be given due attention. Detection workers should strictly comply with the inspection process, to accurate, scientific, fair as a principle, and the detection of each key link in the reasonable control, to prevent unqualified shoddy building materials into the construction site, for the construction project to enhance the overall quality of escort.

References

[1] National Construction Engineering Quality Supervision and Inspection Center Shanghai Construction Engineering Inspection Industry Association. Construction Engineering Inspection Technology and Management [M]. Beijing: Chemical Industry Press,.2006,.10.

[2] Fu Yuling. Study on the Accuracy of Construction Material Inspection Items and Their Data [J]. China Construction Information,.2006,. (12).

[3] Lin Weimin,. Xie Guofeng... Current Situation and Countermeasures of Construction Engineering Quality Inspection Industry[J]. Fujian Building Materials,.2006,. (01).

[4] Lei Ming,. Li Juping... Discussion on the related technology of detecting construction materials[J]. Jiangxi Building Materials,.2012,. (01)...

[5] Huang Zewu.... Talk about how to improve the accuracy of the detection and test results of construction materials [J]. Science and technology and enterprise. .2011,. (07)...

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