（2） Machinery and equipment: grinding wheel cutting machine, electric welding machine, air compressor, electric hammer.
2.
The width of waterstop shall not be less than 50cm, the connection shall be hot pressed welding, and the joint shall not be set at the corner.
The short reinforcement head shall be set in the middle of the steel plate.
（3） Key points for quality control of post cast strip chiseling 1.
Manual hammer + chisel or electric hammer shall be used to chisel, steel wire mesh and loose concrete on both sides shall be removed, and complete and rough stone surface shall be exposed.
The water stop steel plate shall be connected by welding, and the weld shall be tight and full without missing welding.
3.
The curing time shall be no less than 14 days…
5.
（4） Key points for quality control of concrete pouring and curing 1.
The joint review of construction drawings has been completed, and the drawings have been reviewed and sealed for confirmation.
3.
4.
Due to the expansion effect of the post cast strip after pouring, during pouring, the post cast surface is about 5mm lower than the bottom plate surface on both sides.
2.
3.
Key points of bottom slab reinforcement binding Construction: the bottom reinforcement binding shall be horizontal and vertical, and a horizontal reinforcement shall be bound close to the elastic line at the elastic line position for the welding of short reinforcement head of water stop steel plate.
The steel plate shall be fixed according to the 20-30cm short reinforcement head to ensure the stability and reliability of the steel plate.
2.
The waterstop shall be fixed with special reinforcement and bound with the bottom plate reinforcement to form a stable structure.
7 key points of post cast strip chiseling Construction: chiseling shall be carried out after the concrete reaches the 28 day deadline.
The limited expansion rate of concrete shall meet the design requirements, and the grade shall be one grade higher than that of concrete on both sides.
The installation of water stop steel plate shall pay attention to the direction of facing the water surface, and reverse installation is not allowed.
4.
Foundation dewatering measures have been in place to ensure that the groundwater level is lower than that below the working face.
8 key points of construction joint flushing: after removal, use high-pressure water gun to flush the construction joints on both sides, draw out the accumulated water, and manually remove the sundries at the bottom.
Prepare special construction scheme and carry out scheme disclosure and technical disclosure.
4.
4.
Key points of installation and construction of water stop steel plate: the water stop steel plate of post cast strip adopts 4mm thick galvanized steel plate, and the side facing the water surface is bent by 45 degrees.
3.
Key points of steel wire mesh separation construction: after the installation of water stop steel plate, the reinforcement at the upper part of the bottom plate shall be bound.
2.
After chiseling, wash the stone surface with a water gun.
The ponding at the bottom of the post cast strip shall be drained and the sundries shall be cleaned up.
Key points of concrete pouring construction: spray water to wet the surface 1 hour before pouring, pour with micro expansion impermeable concrete one grade higher than the concrete on both sides, and press smooth with a calender after pouring and vibration.
3.
（3） On site preparation 1.
The welding must be fully welded and spot welding is not allowed.
In order to ensure the separation effect of steel wire mesh and quick and easy closing mesh on the concrete on both sides of the post cast strip, the way of setting vertical short reinforcement every 200 ~ 300mm can be adopted as the support back ridge of the steel wire mesh inside the post cast strip.
5 key points of binding construction of bottom plate surface reinforcement: the binding of surface reinforcement shall be horizontal and vertical, and a horizontal reinforcement shall be bound close to the elastic line at the position of elastic line, which is used for welding and fixing the short reinforcement head of water stop steel plate.
The steel wire mesh shall be close to the reinforcement head and set on the side of the pre cast concrete to ensure the buried depth of the water stop steel plate.
9.
The construction of on-site cushion has been completed and the conditions for access and setting out are available.
10 key points of concrete curing construction: different curing measures shall be taken according to the climatic conditions to ensure the moisturizing and thermal insulation of the concrete surface of the post cast strip.
The two water stop steel plates are directly connected by welding.
Control points (I) quality control points of water stop steel plate 1.
Each joint position of the vertical and horizontal reinforcement on the bottom plate shall be fixed with steel wire to avoid slurry leakage.
It is strictly prohibited to weld through the steel plate.
2.
2.
Main tools: pump truck, concrete vibrator, hammer and chisel.
2.
The surface of water stop steel plate shall be free of oil stain, fracture and obvious corrosion.
（2） Key points for quality control of rubber waterstop 1.
In order to ensure the stability of post pouring reinforcement, diagonal bracing shall be set at the same time.
6.
The steel wire mesh shall be close to the reinforcement head and set on the side of the pre cast concrete to ensure the buried depth of the water stop steel plate.
Post cast strip chiseling shall be carried out after the concrete strength reaches 100%.
5.
Each joint position of the vertical and horizontal reinforcement on the bottom plate shall be fixed with steel wire to avoid slurry leakage.
The turning position of the waterstop shall be made into a circular arc.
Construction preparation (I) technical preparation 1.
After the reinforcement is bound, it shall be separated by quick and easy closing mesh or steel wire mesh.
The pouring process shall be continuous to avoid the formation of cold joints, vibrate and compact, and the face shall be flush with the concrete on both sides.
3.
Construction process 1: advance the water stop layer construction and snap the sideline construction key points: advance the water stop layer construction to the same elevation as the waterproof protective layer of the bottom plate, and snap the sideline of the post cast strip after the concrete is hardened.
The concrete pouring shall be watered 1 hour in advance to wet the working surface.
2.
Key points of concrete pouring construction on both sides of the bottom slab post pouring belt: 5cm wood strip baffle shall be set at the upper part of the gluten at the side line of the post pouring belt, which shall be bound and fixed with binding wire and gluten to prevent the concrete from entering the post pouring belt.
The material quality assurance certificate shall be retained and passed the retest, including: rubber waterstop retest report, concrete material certificate, steel waterstop certificate, reinforcement retest report, etc.
The steel plates on both sides of the post cast strip shall be fixed by spot welding between the short reinforcement head and the plate reinforcement to ensure that the water stop steel plates are firmly fixed.
According to the current relevant specifications, this paper introduces the construction preparation, construction technology, construction key points and quality inspection standards in detail for the post cast strip construction of basement floor, which can be used as a reference for everyone.
6.
Chiseling shall ensure that the finished surface is a complete rough stone surface.
The thickness of water stop steel plate is 3mm, the width is not less than 300mm, and the bending is 30-50cm.
