Construction quality control refers to the planning, implementation, inspection and disposal of construction scheme and resource allocation under the guidance of clear quality policy The construction quality control shall implement the idea of comprehensive and whole process quality management, and use the dynamic control principle to control the quality in advance, during and after the event. Next, we will discuss the contents and methods of construction quality control.
Prior quality control
Proactive quality control prior to formal construction Through the preparation of the construction quality plan, the quality objectives are clarified, the construction scheme is formulated, the quality management points are set, the quality responsibilities are implemented, various influencing factors that may lead to the deviation of the quality objectives are analyzed, and effective preventive measures are formulated for these influencing factors to nip the problem in the bud.
In process quality control
In process control is first to restrict the behavior of quality activities, and then to supervise and control the process and results of quality activities.The key to in-process control is to adhere to quality standards, and the focus of control is the control of process quality, work quality and quality control points.
Post event quality control
It is also called quality control after the event, so that the unqualified process or final product (including unit project or the whole project) will not flow into the next process or enter the market. Post control includes the evaluation and identification of quality activity results and the correction of quality deviation. The focus of control is to find defects in construction quality, and put forward measures for construction quality improvement through analysis to keep the quality under control.
General methods for construction quality control
1. Quality document review
2. On site quality inspection
– Inspection before commencement – mainly to check whether the commencement conditions are met
– Process handover inspection – strictly implement the “three inspections” system, namely self inspection, mutual inspection and special inspection. The construction of the next process shall not be carried out without the inspection and approval of the supervising engineer (or the technical director of the owner).
– Inspection of concealed works
– Inspection for resumption of work after suspension
– Inspection after completion of subdivisional and divisional works
– Inspection of finished product protection
Methods of on-site quality inspection
-Visual inspection method: including viewing, touching, knocking and photographing
-Actual measurement method: including leaning, measuring, hanging and sleeve
-Test method: physical and chemical test, NDT
Quality control of construction preparation – prior control
1.Project division
Unit (sub unit) works
Buildings or structures that have independent construction conditions and can form independent use functions are a unit project; For unit works with large building scale, the part that can form independent use function can be divided into several sub unit works.
Divisional (sub divisional) works
The division of divisional works shall be determined according to the nature of disciplines and project parts; When the divisional works are large or complex, they can be divided into several sub divisional works according to material types, construction characteristics, construction procedures, professional systems and categories.
Subdivisional works shall be divided according to main types of work, materials, construction technology, equipment category, etc. It can be composed of one or several inspection lots.
Inspection lot: it can be divided according to the quantities, floors, construction sections, deformation joints, etc. according to the needs of construction, quality control and professional acceptance.
2. Quality control of technical preparation
It is mainly carried out indoors, such as getting familiar with construction drawings, conducting detailed design disclosure and drawing review; Refine the construction technical scheme and the configuration scheme of construction personnel and machines and tools, prepare technical instructions for construction operations, draw various construction details (such as surveying and setting out drawings, detailed drawings, reinforcement, plate, wiring diagrams, etc.), and carry out necessary technical disclosure and technical training.
The quality control of technical preparation, including the review of the above technical preparation results, to check whether these results are free of errors and omissions, whether they meet the requirements of relevant technical specifications and procedures, and the degree of assurance for construction quality; Formulate the construction quality control plan, set up quality control points, and define the quality management points of key parts.
Quality control of site construction preparation
1. Control of project positioning and elevation datum
Engineering Surveying and setting out is the first step for the transformation of construction engineering products from design to physical objects. The construction unit must recheck the original coordinate points, datum lines, benchmarks and other survey control points provided by the construction unit. The retest results shall be reported to the supervising engineer for review and approval before the construction unit can establish the construction survey control network to control the project positioning and elevation datum.
2. Control of construction layout
The employer shall delimit and provide the scope of construction land and site temporary facilities in advance.
Quality control of materials
The construction unit shall control the purchase and ordering, mobilization inspection, storage and use.
1. Purchase and purchase
2. Entry inspection
The use of important building materials must be signed by the supervising engineer and approved by the project manager. If necessary, the supervising engineer shall conduct parallel inspection on the mobilized building materials.
3. Storage and use off
Quality control of construction machinery and equipment
-The selection of mechanical equipment shall be based on the principles of advanced technology, applicable production, reasonable economy, safe use and convenient operation.
– Determination of main performance parameters – the main performance parameters are the basis for selecting mechanical equipment, and the determination of parameter indexes must meet the needs of construction and quality assurance.
– Operation requirements – implement the principles of “work with certificate” and “fixed man-machine”, and implement the use management system of fixed machine, fixed person and fixed post responsibility.