60 common problems and treatment suggestions in construction, novice to veteran

▲ on site Problem: the stone surface on both sides of the garage ramp is wet pasted with alkali.

Cause: when the floor slab is poured and tamped, the upper steel bar is stepped down, which has been bent or only two-way single-layer reinforcement, and the concrete slump is too large.

▲ on site problems: Cracks in the cast-in-situ slab of the delivered building (300 thick fire passage basement roof, C35 concrete and double-layer two-way reinforcement) Moreover, the waterproof construction quality is poor.

Treatment suggestion: pouring During concrete tamping, strictly control the damage and trampling of reinforcement.

Mortar is used as the repair material during repair, and the strength does not meet the specified requirements.


▲ on site problem: the waterproof of the basement roof has been constructed, and micro leakage has occurred at the bottom of the slab, resulting in water printing and mildew.

Treatment suggestion: after honeycomb occurs at the column base, the loose part of the concrete shall be carefully chiseled to the concrete dense layer, and the concrete with higher strength than the original concrete shall be poured Tamping and repairing.

Complete the self waterproof reinforcement of the structure before waterproof construction.

Treatment suggestions: strengthen the phased acceptance of reinforcement works and the side station control of concrete construction, and set the protective layer here densely if necessary.

▲ on site problems: the concrete compactness of the sloping roof is poor, the water leakage treatment is not carried out before the construction of the leveling layer, and the leveling layer does not meet the construction requirements, resulting in serious rainwater leakage after the roof leveling.

▲ Field problem: the waterproofing of basement roof coiled material is constructed on the horizontal plane, resulting in large area of water.

▲ on site problem: the external wall face brick cracks and the large surface falls off.

▲ on site problem: the open joint at the junction of the face brick and the line foot paint is too large and the appearance is poor.

Cause: the construction process is not strictly controlled, and the reinforcement protection is not done well when pouring concrete.

▲ field problem: the plain soil slope of independent foundation does not meet the stress requirements, which is easy to lead to eccentric stress settlement of column foundation after the damage of bearing layer of column foundation.

▲ field problem: lightning strike Lead to the damage of roof sketches (this is not like lightning) Causes: the top of the sketch is the highest point of the building, the top surface is equipped with a metal cover, and the lightning protection network is not led to the top of the sketch, resulting in lightning stroke.

▲ on site problems: the interlayer between the first floor slab and the foundation of the building is not backfilled, and a puddle or pool is formed after rainwater is accumulated.

Cause: the repair materials and methods are not used correctly, and there is no repair scheme.

If the formwork must be removed, replace the support at the same time , the support shall be firm to ensure that the beams and slabs on both sides of the post cast strip are not deformed.

In case of two-way single-layer reinforcement, communicate the adjustment scheme with the designer; strictly control the slump of commercial concrete.

Treatment suggestions: during reinforcement acceptance, check that the column reinforcement is positioned and bound firmly (spot welding can be appropriate), and carefully stand by when pouring and tamping column concrete.

▲ field problem: the structural floor slab has a through crack in the horizontal and vertical directions.

▲ on site problem: pumping commercial concrete beams After the membrane is removed from the slab, there are small holes on the surface, resulting in large-area water leakage.

▲ site problem: there is no protective layer at the bottom of the post cast strip girder in the basement, which seriously violates the specification requirements and affects the service life of the girder.

(in case of large area or deep honeycomb, a special repair scheme shall be prepared and implemented after being submitted to the design for approval) ▲ on site problem: honeycomb and pitted surface are produced due to mortar leakage at the column base.

Causes: the joint of the retaining wall coping stone is not sealed tightly, the joint between the coping stone and the wall stone is not treated with closed water, and the wet pasted mortar is not dense.

Before nailing the mesh, the wall at the part of the mesh shall be paved with 1:3 cement mortar After the first coat of cement mortar is dry and has a certain strength, the steel wire mesh shall be nailed for large surface painting.

Cause: before pouring and tamping the column concrete, the column reinforcement is not made with positioning reinforcement, and the reinforcement cannot be aligned with the upper column reinforcement, resulting in bending.

Treatment suggestions: the mixing ratio of base course painting mortar is no less than 1:3 cement mortar powder, the finished surface of base course painting is free of hollowing, cracks and floating sand, and the wall and face brick are watered and wet the day before laying face brick.

Water leakage at the root of the inner side of the basement outer wall.

If only two sets of formwork are provided, the bottom of the slab should be reinforced and supported with reinforcement when the lower formwork is removed, and attention should be paid to overload construction.

Treatment suggestion: strengthen the inspection and concealed acceptance during reinforcement binding.

The building foundation is soaked in sewage, which seriously affects the service life of the building.

▲ site problems: the reinforcement stacking and reinforcement processing of the basement roof have an impact on the concrete structure.

▲ field problem: after the structural column reinforcement is offset, it is bent at will, which does not meet the structural requirements.

▲ site problem: the post cast strip has no support and the upper part is being loaded for construction.

▲ on site problem: there is a gap in the outer wall and rainwater seeps into the room.

The rainwater flows into the stone mortar layer to carry out the alkali, resulting in alkali flashing.

Treatment suggestions: strictly control the slump of commercial concrete, ensure that the concrete is vibrated tightly during pouring and vibrating, and use a flat plate vibrator for secondary vibration.

▲ on site problem: 45 degree inclined crack of cast-in-situ floor slab.

▲ field problem: the granite stone at the bottom of the beam is separated from the base course and the stone falls off..

The face brick pasting mortar is separated from the painting layer, and the floating sand of the base course is not cleaned before the face brick pasting, forming an isolation layer, The large surface falls off after hollowing; during the construction of face brick, the base course is too dry, the bonding strength between the pasted mortar and the base course is reduced, and it is separated from the base course after the influence of freezing and thawing after rainwater infiltration.

Cause: the construction organization arrangement of the construction unit was not reviewed and monitored in detail.

Treatment suggestion: when the stacking construction is required on the basement roof, the design service load must be clear, and the construction materials must be stacked evenly to avoid overload construction.

Only two sets of formwork are provided for three floors a month, and the lower slab bears the weight of the upper concrete It is suggested that three sets of formwork should be provided for the upper three floors in a month.

▲ on site problems: slurry leakage at the junction of the basement shear wall and the bottom plate causes honeycomb, which is easy to form rainwater leakage points.

Cause: the base course painting quality of the face brick wall is too poor, the strength is low, and the mortar mix proportion is out of control.

Treatment suggestions: during the construction of the retaining wall coping stone, the bottom shall be constructed with wet mortar; the joint joint of the coping stone Squeezing construction shall be carried out to ensure the water tightness of each intersection joint and the compactness of wet grouting mortar.

Treatment suggestions: 1.

Rebar Chair

Treatment suggestions: carefully chisel the loose part of the concrete to the dense layer of the concrete, and pour and tamp it with concrete higher than the strength of the original concrete.

Treatment suggestions: strictly control the slump of commercial concrete, ensure that the concrete is vibrated tightly when pouring and tamping concrete, and focus on the surface or wall with water Process control.

Cause: there are no clear construction measures for the construction and protection of the post cast strip.

Cause: there is no steel mesh reinforcement construction at the part between the infilled wall of the outer wall and the concrete beam.

When removing the formwork for the floor slab, keep the post cast strip formwork and support.

▲ field problem: the cast-in-situ slab has a large area of short-term through cracks.

Treatment suggestions: when the face brick is typesetting, it should be arranged downward from the lower opening of the line foot, and a 10-15mm gap should be reserved at the junction of the face brick and the line foot paint.

After pointing, the paint can be used Turn 5mm downward to ensure the smoothness and straightness of the connecting line.

Treatment suggestion: the joint between the beam column concrete of the outer wall and the brick wall must be nailed with steel mesh greater than 200mm wide.

If limited by conditions, the column bottom elevation shall be adjusted or the soil shall be strengthened.

▲ field problem: the upper reinforcement of the double-layer and two-way reinforcement of the structural slab is sunken.

▲ field problem: the construction quality of rigid waterproof layer of basement roof is poor, which can not meet the requirements of rigid waterproof layer.

When making the formwork for the floor, try to make the formwork for the post cast strip with the formwork on both sides with a separate system.

Treatment suggestion: this place shall meet the requirements for the slope distance of the bearing layer.

Treatment suggestions: after the construction of the roof structural layer is completed, focus on observing whether there are leakage points, and focus on repairing the location where the leakage occurs.

(the specification requires that the indoor backfill should be 200mm higher than the outdoor floor ▲ on site problem: there is serious slurry leakage on the concrete surface, resulting in honeycomb and pitted surface, which affects the service life of the structure.

Cause: the formwork is removed when the lower concrete fails to meet the strength requirements.

If the overlapping part is defective, the coiled material is easy to bulge and disengage, and the rainwater enters the bottom of the coiled material, which is easy to lead to water leakage or mildew at the bottom of basement slab.


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