Hai Chao Wang

Study on the Impact of Polycarboxylic Acid Additive Experimental Process Parameters on Cement Adaptability

By analyzing two Polycarboxylate cement admixture of different polymerization process adaptability, the cement paste experiment is carried out to show the influence of Polycarboxylate superplasticizer, slump agent and the cement synthesis process on cement adaptability. Through orthogonal design method, result is drawn from the comparison of the influence of initial liquidity and an hour liquidity under different conditions,which is base on treating Polymeric acid process parameters as effecting factor within a certain range. It is shown that the preferably optimized process parameters of Polycarboxylic acid exist in the same kind of cement.The system error caused by the impact of cement composition is indicated in different kinds of cement.The adaptability of Polycarboxylic acid cement admixture of the mother liquor is available in the process optimization of the parameters.

Research on the Optimization Method of Compatibility between Polycarboxylic Admixture and Cement

In this paper, the method to adjust the production process of polycarboxylic admixtures mother liquid is researched according to the production of polycarboxylic admixtures. One polycarboxylic admixture cannot be adapted to all cements because of the influence of the mother liquid, although it could be adjusted by composite stabilizer. This paper studies the method of parameter adjustment on the level of factor analysis according to the process of polycarboxylic admixtures. The fluidity of cement slurry test is carried out when the type of cement is changed. On the basis of the test results the parameters are analyzed to design the molecular structure of the polycarboxylic admixtures, which could solve the problem of compatibility between polycarboxylic admixture and cement fundamentally.

Research on the Influences of Crack-Depth Ratio on Fracture Energy of Ultra-High Performance Cementitious Composites

For the study of fracture characteristics of ultra-high performance cementitious composites(ECC),16 different sizes of three-point bending beams were made and ultimate load, ultimate deflection and crack mouth opening displacement ,the curve andcurve of ECC were contructed,with the method of fracture work recommendedby RILEM , the external work was respectively calculated by the curve ofand, which determined the fracture energy of ECC.Results show that two kinds of calculation result are roughly equal;The influence of size effect on fracture character was: fracture energy increased with the increasing of the crack-depth ratio, the fracture energy of concrete specimen is the maximum when the crack-depth ratio is 0.4 ; is proportional to the initial crack-depth of the specimen, but there is no relationship betweenand crack-depth ratio. This paper would have great significance for the study of fracture characteristics of ECC.

The Comparison of Self-Compacting Rock-Filled Concrete with Large-Size Natural and Recycled Aggregate

The different fracture characteristics of self-compacting rock-filled concrete with large-size natural and recycled aggregate are analyzed by three-point bending experiment. According to the analysis of the crack propagation process, the fracture mechanism differences of self-compacting rock-filled concrete with large-size natural and recycled aggregate are discussed. The further analysis of the differences of fracture toughness, fracture energy, and are gain

Study on the Influence from Concrete Mixture Proportions to Polycarboxylate Super Plasticizer Utility

In this paper,study the influence from concrete mixture proportions to poly carboxylate super plasticizer utility, discuss the net of gelled material pulp of liquidity and concrete slump collapse performance issues,analysis fresh concrete and gradation impact on the performance of concrete ,according to the concrete engineering practice.The conclusion is that the above situation can give an explanation in the super plasticizer mechanism level,and can be used in the selective use of admixture ,as well as reference for the choice of materials of concrete .

Study of Sleeper Concrete early Strength Based on Orthogonal Experiment

Using orthogonal design method of four factors and three levels, make a mix ratio experiment on sleeper concrete of Chinas railway sleepers, used steam curing concrete early compressive strength (stripping strength) as evaluation index. Study on different experimental factors of water-cement ratio, sand ratio, fly ash and admixture differently influenced on the early strength of sleeper concrete and analyze the difference impact of each factor and level for the orthogonal experiment. The result shows that the admixture is the main factor for early strength of concrete, followed by fly ash, water-cement ratio and sand ratio. It can provide technical guidance for railway sleeper field and has practical value.

Study on the Compression Capacity of the Wall of Recycled Aggregates Self-Compacting Rock-Filled Concrete

The goal of the paper is to make good use of solid wastes. The aggregates of ordinary self-compacting concrete are changed for the large size of recycled aggregate, which are randomly put into the mold before self-compacting concrete are poured into to form the new type of concrete specimens, and a freestone aggregate specimen is also made for a comparison. 500 tons of electro-hydraulic servo testing machine is used for the test, to measure the strength of this new wall material, bearing capacity, deformation properties and damage form, etc. Test results show that the average compressive strength of the wall of recycled aggregate rock-filled concrete is 6.42MPa, which is far greater than 2.03MPa specified in standard under same mortar strength. Therefore, the recycled aggregate concrete wall of self-compacting has higher bearing capacity, and can meet the requirment of the project.

Study on Strength Mechanism of Self-Compacting Rock-Fill Concrete with Big Aggregates

Self-compacting rock-fill concrete with natural and recycled aggregate can be applied in large structural components’production. According to the deep analysis of materials mechanical properties test data, the author makes a study on the strength mechanism of the concrete material. The results show that the concrete material essentially is concrete, and the concrete strength of large-sized natural aggregate and recycled aggregate are basically the same. However, due to the varieties in material production process and material shape as well as the influence of the mechanical properties and aggregate size, the strength mechanism of them is different. Effective control on mechanical properties of self-compacting rock-fill concrete and aggregates appearances and shapes is helpful to the strength design of the self-compacting rock-fill concrete with large aggregate.

The Creep Impact on the Performance of Super-Long Reinforced Concrete Structures

In order to study the deformation of super-long structures under the influence of creep , take fully advantage of orthogonal design to make nine series reinforced concrete beams of shrinkage-compensating to deeply analyze the function performanced by creep of the reinforced concrete structure and obtain that the time-deflection curves of volume deformation and creep deformation of shrinkage-compensating reinforced concrete beams. The results show that the creep of beams develops rapidly early and the slow development of the late. The greater the expansion stress is in the early, the greater the shrinkage strain in the late, the greater the deformation of volume. So, the appropriate mixing ratio of expansive agent is given by the experiment. It provides a scientific basis for seamless design of super-long structures.

Study on the Material Mechanical Performance of Large Scale Self-Compacting Rock-Filled Concrete

In order to study the influence of large size aggregate on self-compacting rock-filled concrete, the compactness between self-compacting concrete (SCC) and rocks, as well as the whole workability of self-compacting rock-filled concrete, the experimental test in the present paper was carried out on the 500-ton electro-hydraulic serve testing machine and the sizes of specimens are 450mm×450mm×450mm and 450mm×450mm×900mm. The results show that the exterior damage of self-compacting rock-filled concrete specimens are different from that of standard concrete specimens; the damage sections are flat and rocks are cut through in some areas, which shows mainly bond failure at interfaces between self-compacting concrete (SCC) and rocks. The compactness inside is well and the strength of self-compacting rock-filled concrete can almost reach that of SCC, which provides theoretical basis for the application of self-compacting rock-filled concrete.