Key points of steel fiber concrete construction
(1)Foundation treatment: removing debris on the gravel layer and watering to become moist. Gravel surface layer is made of fine sand pave caulking, plastic sheeting on the bedding layer. As a result of the construction method using hops warehouse construction, the concrete that has completed should be cut flat processing, in the concrete form removal, cutting with the blade, making it flat (where the vertical and horizontal slits cut in the future is the bit Ge), can be carried out after treatment construction.
(2) slump Requirements: the reinforcement concrete used by the project is mixed in the concrete mixing plants, feeding on forklifts, earth pumping. Steel fiber feed cement, sand and gravel material was stirred on simultaneously. To ensure the quality of concrete and ground floor pumping smoothly, ask to control 10-14cm
slump
(3) steel fiber concrete construction: according to the characteristics of steel fiber reinforced concrete, mixing station with a large power is required to ensure that the steel fibers not agglomerate, distribution, stirred not more than 80% of the nominal amount of mixing. For concrete mixing requirements: the tolerance of the various raw materials measurement is in line with national regulatory requirements, each plate cement ± 2%, coarse and fine aggregate ± 3%, admixtures ± 2%, admixtures ± 2%. In order to ensure the quality of each dish accurate concrete raw materials, mixing station must be periodically verify various measuring instruments, maintaining accurate; coarse and fine aggregate moisture content should be measured regularly, if worked in rain,should increased construction times of measurement. Concrete foreman in charge of construction, quality inspector, technical director often inspect to the mixing station, must participate in the opening identify concrete. The used steel fiber dosage is according to the requirements according to design documents, each weighing tank mixing concrete.
(4) The framework supporting: 200 # channel steel as a cushion template, according to the construction segment,the supporting templates are divided in turn. The templates side are fixed ensuring that the template straight and stable. First in the lower side of the mold do ash cake, to control elevation, spaced not more than 1500mm. Use the channel spacing 2m per set aside at the disposal of a hole to be side-form top elevation to meet the design requirements of post holes for the steel rod driven into the ground from under the side of the mold to make channel level fixed spot welding, and then the channel with the bottom of the lateral and vertical steel rod spot welding stick and channels, so that the longitudinal fixed, so as to strictly control the side mold elevation requirements.
(5) steel fiber quality assurance measures: The steel fibers with the bag packing is in storage and transport, it is required waterproofing packing material to prevent rusting steel fibers, prohibit weight (eg stampede steel fibers) to prevent agglomeration of steel fiber. When the designated person by the Party A put in gravel in live, gradedly put steel fiber and pick away the agglomerated steel fibers in the bag, add the same weight of steel fiber not agglomerated.
(6) The concrete should be continuous poured, one-time forming a molding. If a interrupt is occurred when pouring concrete, compressive strength of concrete to be reached 1.2Mpa (12 kg / c㎡),the pouring can be went on. The time not be less than 24h. Before continuing pouring concrete on the hardened concrete surface, firstly clearing rubbish, cement films, loosing gravel and weak concrete layer on the surface, should also cut hair, rinsing well with water and fully wet, the water remaining in the concrete surface should be cleared.
(7) must have someone check the templates, support, buried reinforcement member leaved holes and other states when the perfusion process. If deformed and change are founded, should be trimmed in time.
(8) Tolerance requirements: flatness 5mm; elevation requirements: ± 5mm; thickness requirements: some places no more than 20mm.