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【1】 Precast building seat slurry 1.
Brief introduction to precast building seat slurry.
Precast building seat slurry is a special dry concrete mortar material composed of cement as cementitious material, fine aggregate, additives and other functional materials.
It has good plasticity after mixing with water and early strength, high strength and micro expansion after hardening.
It is suitable for bin division, bin sealing or cushion at the connection joints of precast components.
2、 Product usage 1.
Warehouse separation, warehouse sealing or cushion at the connection joints of precast building components; 2.
Leveling, joint filling and bonding of precast building components; 3.
Installation of mechanical equipment by slurry method.
3、 Performance characteristics 1.
Early strength, high strength and micro expansion; 2.
It can be used after mixing with water, with good plasticity and easy construction; 3.
Good water retention, high bonding strength, crack resistance, anti-seepage and no corrosion to reinforcement.
4、 Technical index inspection items and technical index inspection methods for seat slurry for precast buildings class I and class II table jumping fluidity, mm150 ~ 220gb / T ﹐ 2419 water retention rate,% ≥ 88jgj / T70 ﹐ setting time, min60 ~ 240 compressive strength, mpa1d ≥ 20 ≥ 30GB / T ﹐ 176713d ≥ 35 ≥ 5028d ≥ 60 ≥ 80 vertical expansion rate,% 24h0 02 ~ 0.3gb # 50119-2013 chloride ion content,% ≤ 0.03gb / T # 8077 note: 1.
Class I base slurry should be selected for the base slurry construction of precast concrete construction engineering; Class II base slurry should be selected for the base slurry construction of precast assembled piers and abutments and high-rise cast concrete buildings.
2.
Executive standard: db4401t89-2020 technical specification for application of base slurry for precast components v.
construction method of base slurry for precast buildings (I).
General principles (1) no sundries shall be mixed in the transportation and storage of base slurry.
Seat slurry of different varieties and specifications shall be stored separately.
(2) base slurry shall be stored indoors and moisture-proof measures shall be taken.
(3) the effective storage time of base slurry before unopened packaging shall not be more than 3 months, and it shall be used immediately after unopened packaging.
(4) the mixture beyond the applicable period shall not be mixed after adding dry powder and water again.
（2） Construction preparation (1) mixing machines and maintenance items shall be prepared and inspected before slurry setting construction.
(2) before grouting construction, the working surface shall be cleaned and watered in advance without open water, oil stain, scum and other sundries.
（3） (1) the slurry shall be mechanically mixed with water in strict accordance with the water consumption specified by the product.
(2) the mixing time shall meet the requirements of the manufacturer’s operation manual.
(3) the mixing site should be close to the slurry setting construction site, which can be used as soon as mixing.
（4） Mortar setting construction of precast concrete structure construction works (1) when the mortar setting method is adopted for construction, the mortar setting cushion shall be set before the components are in place, and the mortar shall be fully filled between the connected components.
(2) when the slurry setting method is adopted for construction, the slurry shall be laid in a suitable way according to the component type.
When the installed components are external or internal walls without thermal insulation, the base slurry shall be laid in the form of high in the middle and low on both sides, and the low part shall not be less than the actual joint height.
When the installed components are sandwich insulation wallboard, the base slurry shall be laid from the side with insulation to the inner wall.
(3) when the grouting method is adopted for construction, the auxiliary positioning device shall be used before component installation to ensure that the component is accurately in place when falling, and the temporary fixed support shall be set in time to adjust the perpendicularity of the component.
If it is found that there is a part where the grouting material does not overflow at the edge of the component during the perpendicularity adjustment, the component shall be lifted again immediately, Add base slurry to the missing part and re trim the slope.
(4) when the connected cavity grouting method is adopted for construction, the base slurry shall be used to divide and seal each connected grouting area before grouting construction.
It shall ensure that the column and wall together with the grouting area are unobstructed with the grouting sleeve and exhaust hole after installation, and reliable measures shall be taken to prevent the base slurry from entering the grouting sleeve and exhaust hole during column and wall installation.
(5) when the sleeve shear wall is installed by the connected cavity grouting method, the warehouse separation mark shall be made at the corresponding position of the sleeve shear wall after warehouse separation, and the warehouse separation time shall be recorded for guidance of grouting.
(6) after the warehouse sealing of the connecting grouting area is completed, the grouting operation can be carried out only after the strength of the base slurry meets the grouting pressure demand.
（5） (1) pre assembly shall be carried out before on-site assembly.
After the pre assembly is qualified, slurry setting and formal hoisting shall be carried out.
Connection construction shall be carried out after adjusting the elevation and verticality of precast components.
(2) before slurry setting construction, slurry setting baffle shall be set on the lower components and effectively fixed.
The slurry setting baffle shall be processed and formed with steel.
The baffle height shall not be less than the design thickness of slurry setting cushion, and effective measures shall be taken to prevent slurry leakage.
(3) during slurry setting construction, the slurry mixture shall be poured into the slurry setting baffle and set into an inclined plane with high inside and low outside to ensure that the slurry setting thickness meets the design requirements.
（6） High temperature construction: when the temperature of the grout setting part is greater than 35 ℃, the construction shall be carried out according to the relevant requirements of high-temperature environmental conditions and comply with the following provisions: ⑴ cooling measures shall be taken, and the temperature of the concrete base surface in contact with the grout shall not be greater than 35 ℃; (2) during construction, the temperature of slurry mixture shall not be greater than 30 ℃.
（7） (1) curing shall be carried out in time after grouting construction.
(2) during slurry setting construction, the daily average temperature shall not be lower than 5 ℃.
After slurry setting construction, the exposed part shall be sprayed with curing agent or covered with plastic film for moisture conservation.
(3) the grout cushion shall be in wet state, and the curing time shall not be less than 7d..
