Technical specification for seamless construction of concrete laser screed flooring
A general rule for the seamless construction of a laser screed
1 The construction unit shall carry out the whole process control of seamless construction according to the design requirements, engineering properties, structural characteristics and environmental conditions, etc. according to the special construction plan approved by the approval.
2 Seamless construction should be completed after the foundation treatment, foundation engineering, waterproof engineering and pre-embedded pipe fittings are qualified.
3 Seamless construction should be carried out by jumping the warehouse method (as shown below). The jump distance L should be determined according to the seamless design requirements and the specific conditions of the project.
4 The maximum size of the unilateral side of the seamless construction block should not be greater than 40mx40m, and the interval between adjacent concrete blocks should not be less than 7d. The joints of the jump should meet the requirements of the construction joint.
5 Seamless construction When setting horizontal construction joints, in addition to meeting the design requirements, the intermittent time should be determined according to factors such as concrete crack control requirements, concrete supply capacity, steel reinforcement engineering, and installation of pre-embedded pipe fittings.
B Formwork engineering during laser screed machine construction
1 Seamless construction formwork and bracket system shall comply with the following regulations:
a should meet the requirements of bearing capacity, stiffness and stability, and reliably withstand various types of loads during the construction process;
b should ensure the shape, size and position of the structure and components, to facilitate the installation of steel and concrete;
c should be combined with the concrete pouring body curing method for moisturizing and thermal insulation structure design.
The vertical construction joints reserved for the construction of the 2 jump warehouse method should be separated by steel mesh and free-formed wire mesh.
3 In addition to the current national standards, the time for demolishing the concrete for seamless construction should meet the following requirements:
a mold curing time under normal environmental conditions should not be less than 3d;
b After demoulding, it should prevent cold current attack, sudden cooling and severe dryness, and take insulation and moisturizing measures.
C Reinforcement engineering during laser screed machine construction
1 When seamlessly constructed, the steel bar configuration should meet the following requirements in addition to the design requirements:
a crack-proof structural steel bars should be constructed by structural forces and structural reinforcement;
b should adopt double-layer bidirectional configuration;
c temperature, shrinkage steel reinforcement ratio should not be less than 0.1%, the spacing should not be greater than 200mm.
2 When the concrete surface layer is not allowed to crack, it is advisable to arrange a steel mesh with a diameter of 4 mm and a spacing of 100 mm at a distance of 20 mm from the top surface of the concrete.
3 Rebar and its processing and production shall comply with the provisions of the current national standards.
D Relevant regulations for concrete works using laser screed machine
1 The measurement of raw materials shall comply with the provisions of the current national standards.
2 Concrete mixture mixing and transportation should comply with the current national standards.
3 pumping concrete construction process should comply with the current industry standards.
4 The concrete mold temperature should not exceed 35 °C, the minimum should not be less than 5 °C, and the temperature should be lower than 5 °C, the concrete should adopt corresponding anti-freezing measures.
5 Before the concrete is poured, the debris in the formwork and on the cushion layer should be removed; the foundation soil and the cushion layer with dry surface should be watered and moist.
6 When concrete is poured, the displacement and deformation of the stressed steel bars, the positioning ribs, the embedded parts, etc. should be prevented, and the bleeding of the concrete surface should be removed in time.
7 The concrete pouring process should be carried out in layers. The layered pouring should meet the requirements of the layered vibrating thickness specified in the current national standards. The upper concrete should be poured before the initial concrete is initially set.
8 Concrete pouring and vibrating should comply with the current regulations, and should also meet the following requirements:
a should use a secondary vibrating process;
b The pouring surface should be subjected to secondary squeezing treatment in time.
9 After concrete is poured, it should be moisturized and maintained in time. The moisturizing and curing can be carried out by means of watering, covering and spraying curing agent. The choice of maintenance methods should consider the site conditions, environmental temperature and humidity, component characteristics, technical requirements, construction operations and other factors.
10 Concrete maintenance should comply with the provisions of the current national standards, and should also meet the following requirements:
a should be timely in accordance with the temperature control requirements for dynamic moisturizing insulation maintenance;
b strengthen early maintenance, moisturizing maintenance duration should not be less than 14d;
c should check the integrity of the water retaining layer (plastic film, curing agent coating) in time to keep the concrete surface moist.
11 Seamless construction should determine a reasonable period of time. In case of cold, hot or rainy or snowy weather,
Insulation, moisturizing and rainy season construction must be taken to ensure the quality of concrete pouring. Construction should comply with current national standards.
12 When encountering windy weather, it is advisable to install wind-shielding facilities on the construction work surface, and increase the number of times of pressing on the concrete surface to cover the plastic film and insulation materials in time.