Preparation and Properties Study of a Low-Cost Ammonia Carboxylate Concrete Superplasticizer

2019 ◽  
Vol 11 (11) ◽  
pp. 1603-1606
Author(s):  
Fankui Zeng ◽  
Junce Zhang ◽  
Xiaoning Wei ◽  
Baoping Li
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Low Cost ◽  
Reducing Agent ◽  
Test Results ◽  
Optimum Dosage ◽  
Polycarboxylate Superplasticizer ◽  
Gradual Loss ◽  
New Type

Polycarboxylate superplasticizer is the water reducing agent that has the best application prospect in concrete engineering. In this paper, a new type of polycarboxylate superplasticizer is prepared and its properties, such as dispersibility and water-reducing rate in cement particles, slump degree and slump extension in concrete and gradual loss are tested. The test results reveal that the water-reducing agent solves the problem that the traditional polycarboxylate superplasticizer is too sensitive to the change of dosage and that it has good dispersibility to cement particles. The optimum dosage is 2.3%–2.9% and the water-reducing rate is 25.6%–33.0%. The test proves that the high-performance water-reducing agent has a good water-reducing effect. The concrete fluidity of mixed with water-reducing agent is significantly improved and the compressive strength is also improved.

The ability of high performance concrete to resist high temperature

2017 ◽  
Vol 8 (4) ◽  
pp. 392-401 ◽  
Author(s):  
Hassan A.M. Mhamoud ◽  
Jia Yanmin
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Mass Loss ◽  
High Performance ◽  
Elevated Temperatures ◽  
High Performance Concrete ◽  
Sharp Decrease ◽  
Test Results ◽  
Content Type ◽  
Chinese Standard

Purpose This study aims to focus on the resistance to elevated temperatures of up to 700ºC of high-performance concrete (HPC) compared to ordinary Portland concrete (OPC) with regards to mass loss and residual compressive and flexural strength. Design/methodology/approach Two mixtures were developed to test. The first mixture, OPC, was used as the control, and the second mixture was HPC. After 28 days under water (per Chinese standard), the samples were tested for compressive strength and residual strength. Findings The test results showed that at elevated temperatures of up to 500ºC, each mixture experienced mass loss. Below this temperature, the strength and the mass loss did not differ greatly. Originality/value When adding a 10 per cent silica fume, 25 per cent fly, 25 per cent slag to HPC, the compressive strength increased by 17 per cent and enhanced the residual compressive strength. A sharp decrease was observed in the residual flexural strength of HPC when compared to OPC after exposure to temperatures of 700ºC.

Fabrication of a CuCo2O4/PANI nanocomposite as an advanced electrode for high performance supercapacitors

2020 ◽  
Vol 4 (10) ◽  
pp. 5313-5326 ◽  
Author(s):  
S. Rajkumar ◽  
E. Elanthamilan ◽  
J. Princy Merlin ◽  
I. Jenisha Daisy Priscillal ◽  
I. Sharmila Lydia
Keyword(s):  
Energy Storage ◽  
Electrochemical Performance ◽  
Electrode Material ◽  
High Performance ◽  
Low Cost ◽  
New Type ◽  
Energy Storage Applications

The as-synthesized CuCo2O4/PANI nanocomposite has emerged as a new type of electrode material for energy storage applications due to its low cost and sustainable and high electrochemical performance.

scholarly journals An Unconventional Inchworm Actuator Based on PZT/ERFs Control Technology

2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Guojun Liu ◽  
Yanyan Zhang ◽  
Jianfang Liu ◽  
Jianqiao Li ◽  
Chunxiu Tang ◽  
...  
Keyword(s):  
High Performance ◽  
Control Unit ◽  
Control Technology ◽  
Test Results ◽  
Hydraulic Actuator ◽  
Shear Yield ◽  
Execution Unit ◽  
Development Processes ◽  
New Type ◽  
Static Shear

An unconventional inchworm actuator for precision positioning based on piezoelectric (PZT) actuation and electrorheological fluids (ERFs) control technology is presented. The actuator consists of actuation unit (PZT stack pump), fluid control unit (ERFs valve), and execution unit (hydraulic actuator). In view of smaller deformation of PZT stack, a new structure is designed for actuation unit, which integrates the advantages of two modes (namely, diaphragm type and piston type) of the volume changing of pump chamber. In order to improve the static shear yield strength of ERFs, a composite ERFs valve is designed, which adopts the series-parallel plate compound structure. The prototype of the inchworm actuator has been designed and manufactured in the lab. Systematic test results indicate that the displacement resolution of the unconventional inchworm actuator reaches 0.038 μm, and the maximum driving force and velocity are 42 N, 14.8 mm/s, respectively. The optimal working frequency for the maximum driving velocity is 120 Hz. The complete research and development processes further confirm the feasibility of developing a new type of inchworm actuator with high performance based on PZT actuation and ERFs control technology, which provides a reference for the future development of a new type of actuator.

Study on the Compressive Strength and Mixing of Ultra-High Performance Concrete

2013 ◽  
Vol 357-360 ◽  
pp. 825-828
Author(s):  
Su Li Feng ◽  
Peng Zhao
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Strength Properties ◽  
Test Method ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Ultra High Performance Concrete ◽  
Mixture Ratio

The test in order to obtain liquidity, higher intensity ultra-high performance concrete(UHPC), in the course of preparation, high intensity quartz sand to replace the ordinary sand,reasonable mixture ratio control low water-cement ratio,the incorporation of part of the test piece ofsteel fibers, produced eight specimens . In the ordinary molding and the standard conservation 28d thecase, the ultra-high-performance concrete compressive strength of more than 170MPa.Thepreparation of the test method and test results will provide the basis for further study of the law of themechanical properties of ultra high strength properties of concrete.

scholarly journals The effect of UDMA and Bis-GMA irradiation period on residual monomers in resin packable composite

2019 ◽  
Vol 52 (1) ◽  
pp. 24
Author(s):  
Jayanti Rosha ◽  
Adioro Soetojo ◽  
Putu Dewi Purnama Sari Budha ◽  
M. Mudjiono
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Composite Resin ◽  
Ethanol Solution ◽  
Composite Resins ◽  
Polymerization Process ◽  
Test Results ◽  
Glycol Dimethacrylate ◽  
Irradiation Period ◽  
Urethane Dimethacrylate

Background: Residual monomers are non-polymerized monomers which can cause clinical harm, for example inflammation, to oral cavity tissue while the remaining monomers can potentially be carcinogenic. The more residual monomers that remain due to an imperfect polymerization processes, the lower the compressive strength level and the higher the number of micro slits that can cause secondary caries and tooth sensitivity. Urethane dimethacrylate (UDMA) and bisphenol A glycol dimethacrylate (Bis-GMA) constitute two of the resins most frequently used in packable composites. During the short irradiaton period forming part of the polymerization process, UDMA and Bis-GMA have the potential to produce residual monomers. Purpose: This study aimed to compare the number of residual monomers in packable composite resin following irradiation lasting 1x20 seconds and 2x20 seconds. Methods: 28 samples of cylindrical packable composite with a thickness of 2 mm and a diameter of 5 mm were divided into four groups. Groups 1 and 2 were irradiated for 1x20 seconds, and groups 3 and 4 for 2x20 seconds with the composite subsequently being immersed in ethanol solution for 24 hours. The number of residual monomers using high-performance liquid chromatography (HPLC) devices was calculated and the results statistically analyzed using a Mann-Whitney Test. Results: Repeated irradiation had no effect on the amount of residual monomers in packable composite resins. However, there were differences in the number of residual monomers in the material contained in packable composite resins Bis-GMA and UDMA, while the remaining monomers in UDMA outnumbered those in Bis-GMA. Conclusion: The number of residual monomers in Bis-GMA is lower than in the remaining UDMA after 1x20 seconds irradiation, while the number of residual monomers in Bis-GMA and UDMA following 2x20 seconds irradiation was no different to that after irradiation of 1x20 seconds duration.

Synthesis of Bi2S3/MoS2 Nanorods and Their Enhanced Electrochemical Performance for Aluminum Ion Batteries

2020 ◽  
Vol 17 (3) ◽  
Author(s):  
Shimeng Zhao ◽  
Jialin Li ◽  
Haixia Chen ◽  
Jianxin Zhang
Keyword(s):  
Cathode Materials ◽  
High Performance ◽  
Low Cost ◽  
Specific Capacity ◽  
Discharge Voltage ◽  
Aluminum Ion ◽  
High Charge Density ◽  
Initial Charge ◽  
New Type ◽  
The Stability

Abstract Rechargeable aluminum ion batteries (AIBs) have attracted much attention because of their high charge density, low cost, and low flammability. Transition metal sulfides are a class of cathode materials that have been extensively studied. In this report, Bi2S3 nanorods and Bi2S3/MoS2 nanorods were synthesized by the hydrothermal method as new type of cathode materials for rechargeable AIBs. The diameter of Bi2S3/MoS2 nanorods is 20–100 nm. The Bi2S3 nanorods display high initial charge and discharge capacities of 343.3 and 251 mA h/g with a current density of 1 A/g. The static cycling for the Bi2S3/MoS2 nanorods electrode at 1 A/g denotes high stability with a specific capacity of 132.9 mA h/g after 100 cycles. The charging voltage platform of Bi2S3 nanorods and Bi2S3/MoS2 nanorods is at 1.1–1.4 V, and the discharge voltage platform is at around 0.8 V. The well-defined heterojunction maintains the stability of the Bi2S3 structure during long-term cycling, which is desirable for aluminum ion batteries. This strategy reveals new insights for designing cathode materials of high-performance AIBs.

scholarly journals A Pragmatic and High-Performance Radiative Cooling Coating with Near-Ideal Selective Emissive Spectrum for Passive Cooling

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 144 ◽  
Author(s):  
Mingxue Chen ◽  
Wenqing Li ◽  
Shuang Tao ◽  
Zhenggang Fang ◽  
Chunhua Lu ◽  
...  
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Low Cost ◽  
Passive Cooling ◽  
Radiative Cooling ◽  
Test Results ◽  
External Energy ◽  
Functional Nanoparticles ◽  
Space Cooling ◽  
The Universe

Radiative cooling is a passive cooling technology that can cool a space without any external energy by reflecting sunlight and radiating heat to the universe. Current reported radiative cooling techniques can present good outside test results, however, manufacturing an efficient radiative material which can be applied to the market for large-scale application is still a huge challenge. Here, an effective radiative cooling coating with a near-ideal selective emissive spectrum is prepared based on the molecular vibrations of SiOx, mica, rare earth silicate, and molybdate functional nanoparticles. The radiative cooling coating can theoretically cool 45 °C below the ambient temperature in the nighttime. Polyethylene terephthalate (PET) aluminized film was selected as the coating substrate for its flexibility, low cost, and extensive production. As opposed to the usual investigations that measure the substrate temperature, the radiative cooling coating was made into a cubic box to test its space cooling performance on a rooftop. Results showed that a temperature reduction of 4 ± 0.5 °C was obtained in the nighttime and 1 ± 0.2 °C was achieved in the daytime. Furthermore, the radiative cooling coating is resistant to weathering, fouling, and ultraviolet radiation, and is capable of self-cleaning due to its hydrophobicity. This practical coating may have a significant impact on global energy consumption.

scholarly journals Effects of Water Reducing Admixture on Rheological Properties, Fiber Distribution, and Mechanical Behavior of UHPFRC

2018 ◽  
Vol 9 (1) ◽  
pp. 29 ◽  
Author(s):  
Su-Tae Kang ◽  
Jae Kim ◽  
Bang Lee
Keyword(s):  
Compressive Strength ◽  
Rheological Properties ◽  
High Performance ◽  
Fiber Reinforced Concrete ◽  
Test Results ◽  
Fiber Distribution ◽  
Flexural Performance ◽  
Tensile Performance ◽  
High Performance Fiber ◽  
Hardened Properties

The rheological properties of ultra-high-performance fiber-reinforced concrete (UHPFRC) according to the amount of water reducing admixture (WRA) and their effects on the fiber distribution and the tensile performance of UHPFRC were investigated. Four types of mixtures with a high compressive strength over 150 MPa were designed according to the amount of WRA and the flowability, rheological properties, compressive strength, flexural performance, and fiber distribution were measured. Test results showed that the amount of WRA influences both the freshly mixed and hardened properties. It was also revealed that the flexural strength has a strong correlation with rheological properties, compressive strength, and fiber distribution.

A Study on Precipitation in Clean Micro Alloyed Steels

2001 ◽  
Vol 7 (S2) ◽  
pp. 1264-1265
Author(s):  
Yuanli Wang ◽  
Delu Liu ◽  
Jie Fu ◽  
Jian Zhu
Keyword(s):  
High Performance ◽  
Induction Furnace ◽  
Low Cost ◽  
Microalloyed Steels ◽  
Vacuum Induction Furnace ◽  
Low Carbon ◽  
Dominant Component ◽  
New Type ◽  
New Generation ◽  
Impurity Elements

Much attention has been devoted to develop the new generation of microalloyed steels in recent years to meet the needs of high performance and low cost for the 21st century. The new type of steels is characterized by reduced carbon content, improved cleanness and refined grain size through the phase transformations.11'21 Precipitation of the carbonitrides in the steels is also one of the keypoints for controlling mechanical properties of the steels.In the present work ultra-low carbon clean microalloyed steels, which contain 0.029∽0.047(wt)%C, 1.48∽1.54(wt)% Mn, 0.044∽0.052(wt)%Nb, 0.025∽0.044Ti(wt)%, 0.0015∽0.0020(wt)%B and 0.0045∽0.0070(wt)%N, were prepared in a vacuum induction furnace in laboratory. The contents of S and P of the steels are 0.0005(wt)% and 0.0010∽0.0024(wt)% respectively. Total amount of the impurity elements O, S, P and H in the steels is 0.0061∽0.0077%. Dominant component of the structure in both casting and as-forged samples is acicular ferrite or bainite.

ANALYSIS AND RECOMMENDATIONS ON SANDY CLAY BRICKS WITH CEMENT MIX

2020 ◽  
Vol 92 (6) ◽  
pp. 99-112
Author(s):  
PHARAM SINGH THAPA ◽  
◽  
GOVIND PRASAD LAMICHHANE ◽  
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Cement Content ◽  
Low Cost ◽  
Clay Brick ◽  
Clay Bricks ◽  
Sandy Clay ◽  
Soil Cement ◽  
Structural Durability ◽  
Cement Strength

In order to contribute to the sustainability of the brick construction sector, this work studied the formation of economic and environment friendly sandy clay brick. Therefore, the goal was set to be developed, a “sandy clay brick with cement mix”, which has more structural durability, less weight, low cost, together with high performance with respect to indoor air quality. In this research, variation on soil – cement brick with gradual increase in cement content replacing soil material and how the soil- cement brick may be studied using soil and cement as binder by fulfilling the requirement of National Building Code (NBC). The water cement ratio was kept controlled and all other material properties used were same. The effect was seen on compressive strength because the 28 days strength of brick is slightly more when soil is replaced by 15% cement content then no replacement of soil by cement strength. Taking about 11 samples starting from 0 % to 50 % cement content it was found that sandy clay soil – cement brick with compressive strength up to 23.44 MPa with traditional value may be achieved.

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