Vacuum Concrete Construction Method
What is Vacuum Concrete Construction Method？
The vacuum concrete construction method (vacuum hydro-extracting construction method) is the method to remove excessive water inside concrete and air contained in ready-mixed concrete. The method is operated with a vacuum mat and a vacuum pomp, and starts immediately after the placing process.
Do you know?
The volume of water required for concrete hardening is 35% to 37% of the cement weight. The volume of water used for constructions is larger than that, because some water is necessary to increase the operation efficiency of concrete construction. Such water is excessive water, decreasing the concrete strength.
To increase the strength, we have to decrease the volume of water contained in concrete as small as possible.
Effect of vacuum construction method
Crack prevention, long life, abrasion resistance, shockproof, high adhesion of finishing agent, anti-freeze, and short work period
The plane vacuum construction method provides higher strength than the general construction methods.
Data of comparison with general construction methods
Compressive strength - 28 daysConcrete composition: Cement = 4・1/2 bag/ cubic yards
Test: Leibniz Universitat Hannover (Hanover technical college), Germany
Deflection strengthConcrete composition: Cement = 6・1/2 bag/ cubic yards
Test: E. L. Conwell & Company/ Philadelphia, USA
Abrasion testThe vacuum processing and the machine finishing significantly improve the abrasion resistance performance.
Test: Sweden Material Research Institute
Short curing period
Concrete needs curing period after placing. The vacuum construction method allows reduction of the curing period. For example, when the conventional method needs 1 week (7 days), the vacuum construction method needs just 3 days. Similarly, 4-week (28 days) curing period can be shortened to 7 days.
Factory, parking lot, warehouse
The vacuum processing reduces contractility by improvement of adhesiveness to the deck and reduction in the mix ratio of water and cement. The abrasion resistance and freezing damage resistance are also improved.
Improvement of adhesiveness for factory, office, bridge, pier, ice skating rink, parking lot, and two layers construction. Prevention of shrinkage and cracking. Improvement of antifreeze performance.
