Applied Research on the Self- Compacting Concrete in Structure Reinforcement Project
|Keywords||Structural reinforcement Self-compacting concrete Polycarboxylate superplasticizer Interfacial bond Elastic modulus|
Self-compacting concrete used more and more widely, the frequency of use is getting higher and higher. For more and more self-compacting concrete, self-compacting concrete work performance, mechanical properties, deformation properties, durability, construction performance and economic benefits and other aspects. In this paper, the existence of self-compacting concrete applied to structural reinforcement works, the main contents of the study include: reinforcement of self-compacting concrete materials research to determine suitable superplasticizer and cementitious materials; reinforced self-compacting concrete mix design method by contrast common design approach, combined with the reinforcement engineering characteristics of a simple, fast, and applicable mix design method; fresh reinforced self-compacting concrete work evaluation method used to establish a simple, fast, to facilitate the operation of the project site evaluation methods; hardening reinforcing properties of self-compacting concrete, according to the characteristics of force structure reinforcement works to study the interfacial bond strength of new and old concrete, self-compacting concrete elastic modulus, expansion of performance, the early strength of concrete development process. The main research results are as follows: (1) reinforcement through a series of self-compacting concrete raw material selection and optimization of slurry fluidity test, select the Polycarboxylate Fox-80 as a self-compacting concrete superplasticizer, Fox-80 advantages obvious: Content small, the optimal dosage of 0.30%; initial fluidity saturated ash cement paste initial flow reaches 310mm; fluidity and the loss of small saturation dosage, 60min fluidity little losses. The fluidity test to determine the cementitious materials for cement: silica fume: fly ash: slag: expansive agent = 66:4:10:10:10. (2) reinforcing the performance requirements of self-compacting concrete, self-compacting concrete mix design method combined with reinforcement works are determined to reinforce self-compacting concrete with the selected range of values than the three important parameters: the absolute volume of coarse aggregate VG 280 ~ 350L water consumption W 155 ~ 180L, gouache ratio W / P 0.291 to 0.393. Slurry amount is calculated to meet the work requirements for powder amount VCF should to 160 ~ 230L, the slurry the amount VCF W Va should be 320 ~ 400L. (3) reinforcement of the combination of reinforcement engineering characteristics of fresh self-compacting concrete work evaluation method, a simple, fast, and easy operation of the project site evaluation method, select the slump cone test, test slump extended degree edge difference and visual stability evaluation of concrete work. Reinforcing self-compacting concrete slump the extension degrees to 650 ± 50mm, side difference lt; 20mm. (4) hardened reinforced with reinforced self-compacting concrete performance work and good self-compacting concrete and old concrete interfacial bond strength is high; reinforced self-compacting concrete elastic modulus low strength grade ordinary elastic modulus of concrete; 0.023%; 3d vertical expansion rate of self-compacting concrete reinforced with self-compacting concrete and rapid early strength development C55 benchmark with the than 1d cube compressive strength reached 29.3MPa, 28d cube compressive strength of 45%.