Jun Zhe Liu

Research on Influence of Chloride Ion in Sea Sand on the Performance of Concrete

Sea sand concrete is a kind of concrete in which mixed sea sand as fine aggregate, which is large-scale application in the coastal areas in recent years, especially in Ningbo area. The sea sand solves the problem of river sand shortage, coupled with cheaper price, most of the ready-mixed concrete companies are willing to use desalted sea sand instead of river sand. Many companies even are using sea sand without any treatments.In Ningbo sea sand concrete using wide range of usage is not optimistic. This survey and analysis in Ningbo area physical characteristics of concrete using sea sand and sea-sand. On this basis, chloride simulating sea sand, mixed with desalted sea sand, not desalted sea sand mortar strength measurement, the concrete strength rule were analyzed, and discovered the early strength for the sea sand concrete by the presence of chloride.

Influence of Air Entraining Agent on Performance of Inorganic Thermal Insulating Mortar

This paper presents a laboratory study on the effect of air entraining agent on the performance of thermal insulating mortar with glazed hollow bead. The test results show that with the dosage of air entraining agent increases, the consistency of thermal insulating mortar increases, apparent density, thermal conductivity and drying shrinkage decline, However, the compressive strength greater losses owing to excessive consumption of air entraining agent; air entraining agent within a certain dosage can significantly improve the operating performance of thermal insulation mortar, increase its consistency and reduce its apparent density, thermal conductivity coefficient and drying shrinkage. Due to excessive addition of air entraining agent, the apparent density, thermal conductivity and compressive strength of thermal insulation mortar all increase. For a specific insulation mortar, there will exist the best mixing amount of air entraining agent.

Research and Development Display Agent Determination of Nitrite Content in Concrete

The invention relates to building materials field, especially the determination method relates to a concrete root ion content of nitrite. Nitrite as antifreeze in the concrete, early strength agent and rust resistance agent composition is widely used in reinforced concrete structure, the admixture of cement quality generally accounted for 1-3% range, its content is too little and too much will affect the durability and workability of concrete, if insufficient dosage when the early strength, anti-freezing and anti-rust effect is not obvious，otherwise affect the workability and durability，when used as a rust inhibitor and dispersant, insufficient dosage, sometimes, can produce local corrosion and accelerate the macro cell corrosion.Therefore, the determination of nitrite ion content in root of concrete (or mortar) has become the inevitable trend of modern concrete production.

Study on Optimal Ratio of Compound Corrosion Inhibitors for Reinforcing Steel

In this paper, the anticorrosive effects of two types of corrosion inhibitors (anodic inhibitors and cathodic inhibitors) on rebars immersed in the simulated concrete pore solution with 3.5%( wt) NaCl were studied by the static weight loss method . The results are as following: firstly, all of the inhibitors had an anticorrosive effect on the rebars and sodium nitrite performed best. Besides, the higher the concentration, the more obvious effect .Secondly, diethanolamine had the best performance in the cathodic inhibitors. Thirdly, sodium nitrite had a good coordination effect with diethanolamine instead of being used alone. In this way, it can exist synergy and reduce the activity of cathode and anode by the formation of consecutively protective film on the surface of the rebars.

Chlorine Salt to Sea Sand the Influence of Concrete Compactness

The application of Sea sand concrete, to solve the problem of affecting the durability become focus. Chlorine salt is sea sand concrete part. Based on cement, fly ash, sand, the desalination sea sand as experimental material. In were magnified 100 times, 1000 times and 8000 times of HCA0 (blending 0.01% chlorine ion without fly ash concrete), HCB0 (blending 0.03% chlorine ion), HCC0 (blending 0.06% chlorine ion) and HCD0 (blending 0. 1% chlorine ion) 28 days instar glue sand internal scanned , Using XRD analysis method, the chlorine salt to sea sand concrete microscopic morphology compactness was studied. The results of the study show that the microscopic morphology observation, chlorine salt to sea sand concrete compactness impact is not big, but chlorine salt can improve the compactness of concrete.

Preparation and Experimental Study on a New Type of Exterior Wall Putty

With the rapid development of construction industry, the amount of architectural coatings, especially exterior wall coatings, is growing year by year. However, more common problems of construction quality arise with the increase of project amount. Exterior wall putty is leveling material of the protective layer, and putty fitting for external thermal insulation system should have a high bonding strength, good performance of crack resistance and excellent resistance to water. The basic material in this paper is cement and coarse whiting, talcum powder and quartz powder are the fillers. Then the basic mix of putty will be got through orthogonal experimental design. In order to improve the performance and research inorganic materials and associated auxiliary for external wall putty performance impact, pasty exterior wall putty can be prepared through mechanical mixing and by adding some relevant inorganic materials and auxiliaries. Results indicate that this kind of exterior wall putty is easy to burnish the powder and have good performances of workability, water resistance, high bonding strength and dynamic crack resistance. Which has better performances than that sold in market, especially for the performances of bond strength, dynamic crack resistance and water absorpution.

Research on Influence of Fly Ash on the the Microstructural Characteristics of Sea Sand Concrete

By using the electron microscope scanner, we have done some research and analysis about the internal microcosmic structure of sea sand concrete. And combined with micro-XRD analysis as well integrative thermal analysis, we made observations of the internal composition of sea sand concrete., studying the effect on which sea sand makes during concrete hydration and the effect which fly ash made on the micro-structural characteristics of sea sand concrete.

Effect of Binders Combination on Porosity of Steam-Cured Concrete

Under steam curing condition, there is significant increment in the porosity of concrete. For the purpose of reducing porosity of steam-cured concrete and improving the durability of steam-cured precast elements, this paper carried out contrastive experiments including two curing condition (steam curing and standard curing), simultaneously considering the effect of different binders type, investigated the porosity change of steam curing and standard curing concretes with mineral admixtures. The corresponding mechanism was also discussed. Results indicated that, taking replace of 30% cement with double-mixing fly ash and silica fume achieves the lowest steam-cured concrete porosity. Steam curing technological measures exert a significant influence on the steam-cured concrete unclosed top suface porosity. For the characteristics of different concrete mixtures, the same steam curing technological measures exert different influence. For the same concrete, adopting appropriate technological measures can greatly decreased the porosity of concrete surface to be exposed, especially for concrete with high water-binder ratio.

Study on the Strength of Sea Sand Concrete in Ningbo

This paper mainly explain and expounded folding compressive strength of the different types of sea sand mortar , fly ash to the sea sand concretes mortar intensity influence as well as the chloride ion content to the sea sand concretes mortar intensity influence. The pulverized fly ash has the postponement function to the sea sand concretes early strength, the chloride ion has the promoter action to the sea sand concretes early strength. 20% pulverized fly ash be good to the sea sand concretes long-term strength development influence, can achieve the goal which enhances the sea sand concretes the long-term strength . The chloride ion is greater to the concretes early strength influence, especially in previous 3 days. Along with the time development, the chloride ion influence weakens, but the pulverized fly ash enlarges to the concretes intensitys influence factor. A two-phase arrived, the final concrete strength values close to each other.

Study on the Chloride Contents of Sea Sand in Ningbo

This paper is to study the sand concrete, sand is mixed with sand as fine aggregate in concrete, in recent years by large-scale applications in the coastal areas, especially in Ningbo, a coastal river sand shortage is resolved this problem, coupled with low prices, most of the commercial concrete companies are willing to play down the use of sand instead of river sand, the paper surveys and analyzes the use of sea sand in Ningbo and the physical characteristics of sea sand, on this basis, simulates sand chloride doped, dilute sea sand, not dilute sand sea sand and fly ash concrete mortar strength was measured to analyze the strength of law, by comparison analysis, the presence of chloride in the early strength concrete sand.