Introduction
Substandard works within the construction industries and those carried out by the untrained personnel would not only affect the quality of the buildings but also be a threat to public safety, moreover, to the constructors themselves. In a situation of such serious case, the construction industries that were concerned may be held responsible and as such result in damaging their reputation. Therefore, corruption within the construction industries should be avoided as it has devastating effects to everyone. Construction quality control in civil engineering involves the process of testing and inspections to ensure compliance with the minimum standards of the materials and workmanship to be used before, during and after the construction process to achieve the performance of the facility according to the design. Fox and Cornell (1984) observed that since the cost of materials and workmanship involved in the construction projects are substantially high, the process is corruption prone hence there is aim to provide quality control of the materials and works before and during the construction processes. The paper therefore aims at examining the construction quality control process on materials and how the quality control affects the quality of sites.
The implicit assumptions involved in quality control are that of acceptable quality level and total quality control. For the acceptable quality level, there is allowable fraction of defective items, the materials acquired from the supplies are inspected and passed as accepted on condition that the estimated defective percentage is to be within the acceptable quality level. In contrary, the total quality control process do not allow defective items anywhere in the construction process. The process objective to institutions is to never get satisfied with its quality control program even if the defects were reduced to minimal levels (Fox et al., 1984).
The main factor influencing the profitability and efficiency of a completed construction facility to be proven as durable and reliable is the quality of the construction materials that are used; therefore, the defects at the construction facilities are as a result of deviation from the construction standards and regulations in the process of work performances at the site. In order therefore to ensure compliance of the materials, statistical methods and random samples acquired from such materials are normally used as the basic for accepting or rejecting a completed work and batches of materials (Blasland, Bouck & Lee, 2006). In the process, batches are rejected based either on the violation of the relevant design specifications or non-conformance.
Construction quality control process on materials
In order therefore for a construction company to be able to carry out an effective and reliable quality control on the materials and workmanship that they would like to use, the following procedure should be setup and followed.
Code of conduct
Under this section, the responsible parties (preferably the project owner and the consultant) involved in the project; appoint the testing laboratories to conduct the quality control test, issue code of conduct that shall be used to provide guidelines to the employees on ethical practices while dealing with work related issues:
- Rules for protection and use of confidential information with the site.
- Guidelines for declaration of conflict of interest and procedures for handling such conflicts.
- The company’s core values, mission and vision.
Setting up a quality management system
An adequate, experience and adequate quality manager in the field of quality assurance (Blasland et al., 2006). The quality manager develops a quality management system and put in place measures to ensure compliance with the quality requirement specified by the contractor and conducts technical audits on the quality of work for safety critical processes on site and compiles reports. In addition, the project owner is charged with the mandate of reviewing the quality audit report and follow up on the recommendation for improvement.
Components of a quality management system
Blasland et al. (2006) reviews a number of sections that are being overseen by the project team owner and or the consultant. They engage the testing laboratories to carry out some sampling and testing of material to avoid the contractor from hiring test laboratories as it could arise to conflict of interest. Moreover, they define all the quality requirements, standards, frequencies and acceptance criteria for the materials and complete work.
Management of quality control test
Under this section, the consultant is highly responsible, gives direction and oversees the management of most of the control test. He or she issues the formal job instructions to the testing laboratory and obtains approval of the team project owners’ for any variations to the scope of tests specified on the work contract. The consultant ensures that the sampling rate produce a statistically representative sample for the control purpose, moreover, for integrity of the samples results; he prohibits the contractors from participating in any activity involving testing except under supervision and proper documentation of the hand-over of samples to the laboratory (Fox et al., 1984). Therefore, during the management process, the consultant assisted by the testing laboratory ensures that the parallel testing of materials is conducted and that the samples are correctly identified to avoid any confusion.
Statistical methods are scientific procedural processes that are used to interpret the result of test on a small sample so as to reach a conclusion concerning the acceptability of the entire lot or batch of materials and work products. An ideal quality control exercise requires that all materials and work on a facility be tested. However, exhaustive testing by inspectors is expensive and time consuming and as a result, small samples are normally used to establish the basis of either accepting or rejecting some work or materials (Liebermann, Ang, Bolt & Tang, 1795).
The assumption made is that samples are normally the representative of the entire population being considered and are chosen randomly so as to be able to represent each and every member of the population (Fox et al., 1984). Therefore, a convenient sampling plan that can give comprehensive information about the samples should be adopted, such as sampling every fifth piece. Sampling can be done by either considering the attribute properties of the materials as defective (bad) and non-defective (good) or considering them as variables where the value of a measured variable is used as a quality indicator. The process is aimed at determining the acceptance quality of particular groups of materials and works.
The results attained from the small samples of testing can be misleading and even seems to give wrong information if they are not properly interpreted; Statistics is therefore used to adequately interpret and analyze the acquired results of testing and due its random nature of sample selection process, testing results are always substantial. Therefore, it is only with statistical methods that chances and probabilities of different levels of defective items can analyze from such small samples (Blasland et al., 2006).
An implicit assumption in quality control by statistical method procedures is that the materials and works have different quality and are therefore expected from one another. The variations in material properties, manufacturing and temperature during setting, ensure that concrete is heterogeneous in quality (Liebermann et al., 1795). Therefore, as a quality controller at the construction site, one should ensure that the materials used acquire the minimum quality level as recommend by the designer.
Documentation of test results
The test certification and reports are generated by the testing laboratory and amended by the project consultant who either rejects the test report and the certification if the results have been altered in any manner or he accepts the amendments to the test result if they are certified by the responsible staff member of the laboratory (Blasland et al., 2006). The testing laboratory should document the following while preparing their reports:
- The name, title and roles of the independent witness who attended the test.
- The precise identification and description of the sample, component or item tested, together with any distinguishing characteristics.
- They should uniquely identify the certificate or report with serial number pages and the total page number quoted.
- The measurements and results providing additional sketches, tables, graphs, and photographs as appropriate.
They should employ a standard documentation format of their reports to ensure that all the necessary information that is obtained from the test is uniformly entered. This ensures neatness and easy comparison process of the data collected, finally the results and the report should be handed over to the team project owner’s or the consultant in a sealed envelop without routing through any place or person.
Monitoring testing laboratories’ performance
It is important to assess and monitory the performance of any work result so as to know and improve on its areas of weakness. The team project owner is the party responsible for assessing and monitoring the performance evaluation of the laboratory results. He steps up an implementation procedure for the appraisal of the testing services provided at the end of the contract for recording of adverse performance for future use or terminates the contract if the performance was consistently unsatisfactory (Liebermann et al., 1795).
Staff rotation
At the project site, one might realize the potential capability of his or her employee in a different field rather than the one he or she was assigned. Therefore, he consultant can rotate staffs in sensitive jobs such as that of supervision of quality control test on site.
Quality control effects to the construction sites
In order to attain quality control in construction industry, the constructor needs to meet some requirement which will not only concur with his or her requirements and that of the designer but also meet the needs of the flora and fauna. For example, after carrying out a successful quality control to building a dam in an area where people leave, it would therefore require that excavations to be made, people and animals leaving around the area be displaced. As a result, the effect is that people will be left homes and the aesthetic nature of the land destroyed.
Quality control has to be planned just like other aspects of construction management. Planning seeks order and therefore a quality control system for a construction project encompasses this sense of order by planning how to achieve the required quality, construction methods, equipments, personnel and materials to be used (Liebermann et al., 1795). Therefore, the mining pits that area left open after mining are always dangerous to the wild animals and humans; moreover, they are normally regarded to be infertile and as such cannot be used for agricultural purposes. Such construction sites are always left and not put into any use.
People who leave close to the quality control test construction sites may suffer from different types of environmental pollutions. The air around such places may be polluted due to the construction and chemical test that are carried. Poor air quality is the most immediate pollution effect that someone might experience and as a result, airborne contaminants including contaminated particulate matter and volatile compounds are spread around mostly by wind (Fox et al., 1984). The main construction quality control contaminants that spread around by wind are: asbestos and gases such as carbon monoxide, carbon dioxide and nitrogen oxides.
Soil at and around the quality control construction sites may get contaminated as a result air transported chemical substances, spillage from the trucks or people moving around with such chemical and water runoff of construction contaminants (Blasland et al., 2006). The soil may therefore constitute a sink of pollutant that accumulate in it and as a result kill the nutrients. Such construction sites are normally rendered unfertile and therefore no agriculture activities can be carried out around them.
Quality control process at a construction site is normally very noisy and if it involves mining, additional vibrations that are experienced by the neighboring community are always very adverse and therefore can cause serious problems (Liebermann et al., 1795). Noise may adversely affect someone’s health including effects such as stress, sleep disturbance, high blood pressure and even hearing loss. Vibration from such construction works can cause architectural and structural damage to some building, especially unreinforced or older buildings. Although the noise may be adverse and affect the personnel working in such places, modern developed gargets and the preventative measures that people undertake in such construction plants may substantially reduce the amount of noise thus one not affected.
Water is a basic and vital commodity to both the flora and fauna and should be preserved for consumption purposes. The surface runoff and groundwater at and close to a construction site always get polluted with various materials from the construction contaminants. The immediate effect is creating turbidity in the runoff water and affected surface and groundwater (Liebermann et al., 1795). Soil, humans and other domestic animals that may use the water may become contaminated through direct consumption and indirectly by affecting the quality of the indoor air. Water pollution from such sites therefore underestimated and has potential to generate severe environmental problems.
Conclusion.
In order for clients to gain complete trust in construction facilities, construction quality control on materials and workmanship used must be carried out. This will therefore help eliminate the quacks that get involved in construction works and do unprofessional job thereby damaging the trained professionals’ reputation.
Reference
Blasland, Bouck & Lee. (2006). Phase 1 Final Design Report. Hudson River PCBs Superfund Site March, 2006
Fox, A.J. & Cornell, H.A. (1984). American Society of Civil Engineers. Quality in the Constructed Project, New York.
Liebermann, G. J., Ang, A.H.S., Bolt, & W.H. Tang (1795). Environmental Protection Agency. Probability Concepts in Engineering Planning and Design: Volume I - Basic Principles, New York.
