In Vietnam, Xuan Mai Investment and Construction Joint Stock Company (XMC) is the first company to invest in Acotec Xuan Mai Wall Panel Factory to produce precast concrete hollow wall panels by extrusion technology on the construction area. about 1.2ha in Thuy Xuan Tien commune, Chuong My district (Hanoi city) and officially put into production at the end of 2015 with 4 Acotec wall panel production lines with a capacity of 200,000 m2 wall panels/year/line, with the factory output has reached about 1,000,000 m2 of wall panels/year.
The batching plant supplying concrete for the line is imported from the company Frumecar (Spain) which is a special mixing equipment used for small-grained mixtures. Raw materials for the manufacture of acotec sheet forming aggregates include: aggregates of sand, grit (under 7-10mm), cement, additives, and water which are quantified in batches fed to the planetary vertical mixer. The feature of the batching plant is that it has an automatic system to adjust the amount of water supplied to the mixer to reach the moisture content of the mix.
After mixing, the material is fed by the conveyor belt to the feeding system for the elematic extruder. Before feeding into the extruder, the aggregate is sampled to check the actual moisture content. The extruded sheets that do not achieve the appearance are broken and fed back to the dedicated conveyor. The Acotec sheet is cut to size on the extruder conveyor and loaded onto a steel pallet.
Technological parameters of the line: Number of operators: from 2-4 people; Production space: 30×40 m; Power consumption: 50 to 60 KVA; Compressed air consumption: 0.3- 0.5 m3/min; Water consumption: 1.5 m3/h; Consumption of concrete: 4-8 m3/h; Line speed: 2.4 m/min; Total capacity: 80 m2/h.
Acotec Xuan Mai sheet products are moisture-cured in the factory while waiting to reach the strength to remove the support plate, usually the panels are put through the humid heat curing tunnel, then the bottom is separated and packed into bales according to TCVN 11524 :2016.
Acotec Xuan Mai wall panels use: aggregates of sandstone, crushed sand, fine sand (mineral additives), cement, mixing water. Sandstone is used with the largest grain size not larger than 7-10mm, depending on the thickness of the plate. Particle composition of large aggregates using aggregate chart Dmax ≤ 10mm. Crushed sand is used with a modulus of magnitude from 2.6-3.1. (Table 1)
To manufacture Acotec Xuan Mai wall panels by extrusion technology, in addition to fine-grained aggregates, crushed sand also requires a fine-grained content between the cement and sand grains. As a result, it not only ensures the workability of the mix, but also brings the surface of Acotec Xuan Mai wall panels flat and beautiful, without the need to plaster the wall.
Materials used in the production of Acotec Xuan Mai wall panels include: Ordinary aggregates in accordance with TCVN 7570:2006, TCVN 9205:2012, aggregate particle size not larger than 10mm and not exceeding 1/2 of the thickness. wall products; in addition, satisfy the requirements of the design; water for mixing and curing concrete in accordance with TCVN 4506:2012.
Requirements on concrete: The concrete mixture must have a workability suitable to the requirements of extrusion or vibrating technology; compressive strength of concrete at the age of 28 days is guaranteed according to the design requirements but must not be less than 15 MPa; water absorption of concrete, not more than 15 for ordinary hollow wall panels and not more than 12 for soundproof wall panels.
Wall panels after extrusion are cut to the right size and transported to the warehouse via a system of rollers, grabbers and forklifts. Here, concrete wall panels are cured for 24 hours and packed. The entire production process is controlled automatically by a central control system.
After being manufactured at the age of 28 days, the prefabricated wall panels are determined the mechanical and mechanical properties at the factory: the size deviation, the flatness of the wall panel's surface as well as the impact strength, fire resistance... required and above the allowable requirement.
Acotec Xuan Mai wall panels have a length of 2,500-3,600mm; with width 300-600mm, sheet thickness 100mm and 140mm.
Acotec Xuan Mai wall panels are precast concrete hollow wall panels by extrusion technology according to TCVN 11524:2016.