Sandwich insulation panels are also referred to as "sandwich members" and refer to precast concrete members consisting of concrete members, insulation and outer blades. Including "precast concrete sandwich insulation wall panel" "precast concrete sandwich insulation column" "precast concrete sandwich insulation beam". Among them, the most used is the “precast concrete sandwich insulation wall panel”.
At present, there are two methods of sandwiching the insulation wall panel, and there are two methods of operation and two operations. However, there is a large quality and safety concealment in the primary operation method because it cannot accurately control the concrete interval between the inner and outer walls. All the work is completed before the initial setting of the concrete. Some operation links during the initial setting or initial setting directly cause the insulation and the concrete to be wrapped and disturbed, which cannot meet the anchoring requirements. Therefore, I do not recommend using one operation method. Japan's sandwich insulation exterior wall panels are based on two operations, and the European sandwich insulation exterior wallboard production line also uses two operations. The concrete pouring interval between the inner and outer leaf walls is controlled to ensure the anchoring quality of the tie members and the concrete.
1. National Standards
1) The variety, quantity and position of the inner and outer wall of the sandwich insulation wall panel are important for ensuring the safety of the outer wall structure and avoiding wall cracking. The installation must comply with the design requirements and product technical manual.
2) Prefabricated components with thermal insulation materials should be formed by horizontal casting. The sandwich thermal insulation wallboard molding should also meet the following requirements:
1 The number and position of the tie parts should meet the design requirements.
2 Reliable measures should be taken to ensure the position of the tie members and the thickness of the protective layer to ensure reliable anchoring of the tie members in the concrete.
3 should ensure that the insulation material is tightly seamed or sealed with adhesive material.
4 The lower concrete shall not be initially set before the upper concrete is poured.
2, sandwich insulation outside wall plating
There are two types of commonly used thermal insulation tabs, one is a pre-embedded metal pull-tab, the other is a plug-in FRP pull-up, and the FRP is a fiber-reinforced plastic.
1) The tie piece is buried. The embedding of the tie-wraps needs to be considered when pouring the core insulation of the sandwich wall.
1 inserts people. Plug-in for the embedding of FRP pull-tabs.
After the concrete of the outer wall is poured, insert the knots before the initial setting to prevent the knots from being inserted into the concrete after the concrete begins to condense, or the concrete can not be wrapped and the knots are not inserted. It is strictly forbidden to insert the knots through the insulation material. This method of inserting will crush the broken particles of the insulation into the concrete. The broken particles and the concrete together will weaken the anchoring strength of the fasteners. Safety.
2 pre-buried. Pre-embedded for metal pull-tabs.
The tie-tabs that need to be pre-bundled should be installed and bundled in advance before the concrete is poured. After pouring the concrete, it is strictly forbidden to disturb the tie-up parts.
2) The insulation board is laid and the inner leaf board is poured. There are two ways to lay insulation boards and inner leaves:
1 one-time operation method. After the outer wall is poured, the insulative material that has been pre-drilled (the hole of the knot) is laid, and after the pull-tab is inserted, the inner-leaf plate steel and the embedded parts are placed for concealed engineering inspection, and the first wall is condensed. Pre-casting inner wall concrete. This kind of practice is more efficient in one go, but it is easy to cause disturbance to the knotted parts, especially when the inner wall wall is installed with steel bars, embedded parts, concealed works acceptance, etc., it takes more time, when the outer wall concrete begins to condense, the various The working activities will disturb the tensile members and the surrounding concrete, which will seriously affect the anchoring effect of the fasteners and form a hidden danger of quality and safety.
2 two operations. After the outer wall is poured, the insulation tie is embedded in the outer wall concrete before the concrete is initially set. After the concrete is completely solidified and a certain strength is reached, the insulation material is laid and the inner wall concrete is poured. The laying of insulation and the pouring of the inner wall were carried out the next day.
3) The insulation layer is laid.
1 The insulation layer should be laid from the beginning to the middle.
2 As far as possible, use large insulation boards to reduce the thermal bridge caused by the joints.
3 Regardless of whether it is a one-time operation method or a secondary operation method, the pull-up parts should be inserted into the insulation board after drilling.
4 Fill the gaps of the joints or the holes with polyurethane foam.
3, the core insulation insulation wall board production points
1) Before the insulation board is laid, it should be arranged according to the design drawings and construction requirements, and after confirming that the tie-off parts and the insulation board meet the requirements, the drawing parts and the insulation board can be placed, and the insulation board should be closely arranged.
2) The pull-in piece should not be directly inserted into the heat-insulating board in the wet working condition, but the hole should be inserted into the heat-insulating board in advance, and the FRP plastic sheath should be flush with the surface of the heat-insulating material during the insertion process. And rotate 90°.
3) Sandwich insulation wall panels are mainly connected with concrete layers of inner and outer blades by FRP tie-off members or metal pull-up members. During the forming process of the component, the wrong length of the FRP tie-tab or the metal pull-up piece should be ensured, and the concrete slump should be controlled within the range of 140-180 mm to ensure the effective grip force between the concrete and the joint.
4) The core outer wall panel adopting the secondary operation method needs to select the applicable FRP insulation drawing piece, and it is not suitable to use the drawing piece with plastic sheath.
5) When the secondary working method adopts the metal pull-up piece in the vertical state, the heat-insulating plate can be lightly pressed to pass directly through the drawn piece; when the non-vertical state metal-drawn piece is used, the heat-insulating plate should be pre-grooved and then laid. It is necessary to complete the damage to the insulation material during the laying process.
6) When producing the corner or L-shaped sandwich insulation external wall, the upper part of the vertical mold part should be poured simultaneously with the inner and outer concrete layers. Reliable measures should be taken during production to ensure the inner and outer concrete thickness, insulation material and the position of the fasteners are accurate.