Abstract: This paper studies industrial acetone, p-amino benzene sulfonate as raw materials, developed a colorless superplasticizer and the test on its liquidity, solid content, setting time, and the performance of concrete. Finally got this colorless superplasticizer for decorative concrete.
Abstract: At present, the more common materials of exterior insulation in our country are the external heat-insulation wall of polystyrene panel, aerated concrete blocks and thermal insulation coating. Paper analyzes the advantages and disadvantages of these three technologies. The results show that with the same thermal insulation property, the cost of thermal insulation coating is obviously lower than the other two. Meanwhile, the thermal insulation coating has a significant improvement on the anti-fire properties, which can eliminate the potential fire risk which may be caused by the external wall of polystyrene panels. In addition, the thermal insulation coating is more simple to construction. Finally, this paper introduces the development prospects of thermal insulation coating.
Abstract: The aim of this research was to define a rapid and simple test that would indicate the probable performance of a pretreated wood species in a hot-press drying process and the kiln schedule. The drying rate (mass/time) and the remaining mass of water were measured at different moisture intervals. The moisture of timber decreased rapidly and the drying rate was 3.7% per day in the early five days. The timbers were B grade after drying used the hot-press drying kiln in 16 days. The moisture content of timber reached 9.20% after the drying process with the standard deviation of 0.92%. The gradient of the moisture content was 3.40%. The moisture content standard deviation in the thickness of timber was 2.70% and the residual stress was 1.38%. The mechanical properties of impregnation wood improve significantly compared to the untreated wood. The basic density of impregnation wood improved by 17.1%, the over-dried density increased to 0.55 g·cm-3 from 0.49 g·cm-3. The scanning electron microscopy explained the wood modifier has been permeated into the wood fiber which reacted with the wood composition.
Abstract: Seawater and sea sand mixed in concrete will cause rebar of structural concrete corrosion, referring to the principles of composition and design of MCI and Pearson’s Hard-Soft Acid-Base (HSAB) theory, as well as to synergy effect of corrosion inhibitor applied in chemical industry, compound corrosion inhibitor has been designed consisting of diisopropanolamine, surface active agent, inorganic salts and so on. This paper research the relation between polarization potential and time of rebar in seawater-and-sea sand concrete through a series of experiments by adding corrosion inhibitor into seawater-and-sea sand concrete to improve its corrosive resistance characteristics. The results indicate that Z5 has the best inhibition effect. Corrosion inhibitor Z5 comprises 50% of triethanolamine, 20% of dimethylethanolamine (DMEA), 25% of triethoxysilane and 5%lithium nitrate, and its proper content applied in seawater-and-sea sand concrete is 1.5%. Rebar have been embedded in seawater-and-sea sand concrete for the long-term test. The results show that corrosion resistance performance of seawater-and-sea sand concrete with corrosion inhibitor Z5 was significantly improved, and the embedded bar was not corroded at all within 420 days.
Abstract: The progressive collapse of the frame structure is simulated with testing a 1/3 scale, 4×2-bay and 3-storey reinforced concrete spatial frame in this paper. The experimental model was designed according to the non-seismic resistance demand, and the middle-side column of the bottom floor was replaced by a mechanical jack to simulate its initial local damage. Based on the experimental results, the applied load process and the load transferring mechanism of the model frame are analyzed. The progressive collapse-resisting performance of reinforced concrete frames with non-seismic demand are obtained.
Abstract: Everyone knows heavy metals are inorganic pollutants with strong toxicity and typical pollutant needing preferentially control. In the metal mines of China, the tails that were piled up on the ground already have reached more than 4 billion tons, and this number increased 2 ×108 tons every year. The characteristics of metal mine tails mainly include: (1) the grain size is extremely fine; (2) The quantity in weight was very large; (3) the toxicity is very strong; (4) Transporting concentration is very low. The migration of heavy metals would impact the local environment, the safety of the downriver resident and the plowland, the food safety of livestock as well as the solid’s safety. Based on the characteristics of mine tailings impacting to environment, this paper estimates the pollution property, as well as studies the harm for the outside environment through the experiment of the gross analysis and the infusion toxicity analysis. This research takes Longdu tailings of Dahong Mountain for example to know the harm of heavy metal ion.
Abstract: Served as the primary form of joints in aluminum structures, the bolted connection is of great necessity to be investigated. The bearing performance of aluminum alloy bolted connections was evaluated by test and finite element (FE) analysis. A total of 20 bolted connections were tested and the varying parameters incorporated screw diameter and end distance. The test results included the ultimate bearing capacities and relationship between applied load and bolt hole deformation. Numerical simulation for the test process was implemented; thereupon reliability and accuracy of the FE models could be validated by good agreement with test results. By virtue of the verified numerical model, elaborated analysis of principle variables including inner and outer plies, end distance, screw diameter, sheet thickness and so on was carried out. Compared to the current overly conservative design rules, a new design method that could make full use of the bearing capacity was proposed. The corresponding design value of bearing strength was also presented with reference to the recommended constructional provisions.
Abstract: Three point bending tests were carried out on 14mm-thick Q460C the high-strength structural steel at low temperature, and scanning electronic microscope of the fracture appearance was analyzed. The results showed that the obvious feature of brittle mechanism was shown on the three point bending specimen fracture whose testing took place at -40°C. And the crack tip opening displacement value of Q460C steel, which was less than that of Q235 steel, Q345 steel and Q390 steel at low temperature, tended to decrease with respect to the temperature reduction. Moreover, a Boltzmann function fitting analysis was applied to the experimental data, and the ductile-brittle transition temperature and the changing regularity were obtained.
Abstract: Composite slab with steel sheeting deck is considered a continuous slab when it is under a constructional situation. Nevertheless, many recent researches are focused on simply supported slab. In order to determine the load carrying capacity regarding various rebar ratio on negative moment region, a numerical analysis was carried out by using finite element analysis. The result of analysis shows that the reinforced steel rebar increases load carrying capacity. Moreover, it has shown that the reinforced length of steel rebar also affect the load carrying capacity.
Abstract: Section-Ⅲ landside curtain wall of Hefei Xinqiao International Airport terminal adopted single layer cable net curtain wall, while others adopted stick-system curtain wall structure. In this paper, the section-Ⅲ overall structure model of Hefei Xinqiao International Airport terminal was established by using the finite element method (FEM) software ANSYS. The load bearing capacity and deformability of landside curtain wall under load cases with seismic loads and wind loads were analyzed. Also the cable net curtain wall’s effect on the main structure was discussed. The results showed that the displacements of curtain wall and the internal forces of cables met the requirements, and the cable net curtain wall had little effect on the main steel structure.