scholarly journals Fracture Characteristics of Polyurethane Grouting Materials Based on Acoustic Emission Monitoring

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Baihui Ren ◽  
Jianjun Shen ◽  
Weitao Liu ◽  
Yingying Hu ◽  
Qing Cao
Keyword(s):  
Compressive Strength ◽  
Acoustic Emission ◽  
Failure Process ◽  
Testing Machine ◽  
Test Method ◽  
Fracture Characteristics ◽  
Grouting Material ◽  
Orthogonal Test Method ◽  
Grouting Materials ◽  
Polyether Polyol

In this study, 16 groups of tests were designed by the orthogonal test method, and a PU grouting material was prepared, which can be used for the construction of sealing wall in mined-out area of coal mine. The basic properties of the material were measured. Firstly, the viscosity of four groups of samples with different polyether polyol contents was measured by a dynamic rheometer. Secondly, the uniaxial compressive strength of pure slurry samples and sand-containing samples was measured by a universal testing machine. Finally, the failure process of sand-containing samples was monitored by acoustic emission equipment. Through the above research and analysis, a PU grouting material with excellent performance has been obtained. That is, when the ratio of polyether triol:polyether tetraol:catalyst:surfactant:chain extender:plasticizer is 11 : 9 : 0.5 : 1.0 : 1.2 : 6.0, PU grouting material has higher injectability and ideal compressive strength, which has been proved in grouting experiments.

Acoustic Emission Characteristics of Rock Failure under Uniaxial Loading

2011 ◽  
Vol 378-379 ◽  
pp. 43-46 ◽  
Author(s):  
Tao Xie ◽  
Qing Hui Jiang ◽  
Rui Chen ◽  
Wei Zhang
Keyword(s):  
Acoustic Emission ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Progressive Failure ◽  
Failure Process ◽  
Testing Machine ◽  
Rock Failure ◽  
Rock Failure Process ◽  
State Variation ◽  
Acoustic Emission Test

With RMT-150C rock testing machine and AEWIN E1.86 DISP acoustic emission system applied, the acoustic emission test was accomplished with two kinds of rock samples including marble and granite under uniaxial compression. Cyclic loading and continuous loading were used through the experiment, and the mechanical performance and acoustic emission (AE) characteristics were obtained during the process of rock progressive failure. Details related to the relationship between amount of AE and stress-strain was given in this paper. A comparison between marble and granite was made as well following the general AE law, on the basis of which, the failure mechanism of rock mass was investigated. Finally, some conclusions can be summarized as follows:(1) AE activity features are different with stress state variation in rock failure process;(2) loading patterns make a direct impact on the failure process thereby affecting AE activities;(3)AE activities are various basing on the different types of rocks, structures and failure modes.

Experimental Research on Acoustic Emission of Granite under Uniaxial Compression and Splitting Tensile

2012 ◽  
Vol 232 ◽  
pp. 24-27
Author(s):  
Zong Zhan Li ◽  
Jun Lin Tao ◽  
Yi Li
Keyword(s):  
Compressive Strength ◽  
Acoustic Emission ◽  
Uniaxial Compression ◽  
Uniaxial Compressive Strength ◽  
Loading Rate ◽  
Testing Machine ◽  
Peak Stress ◽  
Uniaxial Compression Test ◽  
Peak Strain ◽  
Ae Energy

This paper makes the acoustic emission of granite under uniaxial compression and splitting tensile test by electro-hydraulic testing machine and AE .We studied the relationship of uniaxial compressive strength and splitting tensile strength with the loading rate and AE characteristics of granite .The results show that uniaxial compressive strength and peak strain raise with loading rate, the AE energy gradually increases and get maximum in the 30% of the peak stress in the process of uniaxial compression test, and in the splitting tensile AE energy generates in the initial loading and gets maximum when the granite brittle fracture.

Research on Multivariate Composite Super early Strength Grouting Materials

2013 ◽  
Vol 477-478 ◽  
pp. 990-995
Author(s):  
Xiao Ping Zhang ◽  
Chang Zheng Sun ◽  
Tong Feng Zhao
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Ordinary Portland Cement ◽  
High Alumina ◽  
Flow Ratio ◽  
Initial Flow ◽  
Growth Structure ◽  
Grouting Material ◽  
Early Strength ◽  
Grouting Materials

Super early strength high performance grouting material was produced using high alumina cement, ordinary portland cement, gypsum and silica fume. The different glue sand ratio and the cement sand ratio 1.0 mix microstructure were studied systematically. The results showed that the system with a variety of admixture using hingh mortar ratio can be prepared for the initial flow ratio greater than 325{mm},, 30min flow greater than 280{mm}, 2h compressive strength 34.80{MPa}, 24h bending over 13.82{MPa}, 28d compressive strength greater than 99.90{MPa}, 28d compressive strength greater than 56d compressive strength. The system of early SEM microstructures showed good crystal growth, structure compact.

scholarly journals Experimental Study on the Influence of PVA Content on the Performance of Grouting Material in Deep Stope

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Bin Liu ◽  
Liming Yin ◽  
Juntao Chen ◽  
Ming Li ◽  
Daozeng Tang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Setting Time ◽  
Practical Significance ◽  
Peak Period ◽  
Grouting Material ◽  
Coupling Characteristics ◽  
Grouting Materials ◽  
And Control ◽  
Water Hazards

Based on laboratory experiments, the paper researches the effect of polyvinyl alcohol (PVA) content on the performance of fly ash-based cement grouting materials. The test results show that the addition of PVA has limited effect on the initial and final setting time and brings a certain but minor delay on the appearance of the hydration peak period. It enhances cement hydration during the hydration slow down period. The impermeability of PVA to the grouting material is obviously improved, and it increases with the growing amount of PVA content. PVA improves the flexural strength and compressive strength of the sample block to varying degrees, and the improvement on flexural strength is more obvious than that on the compressive strength. It has a significant effect on the mechanical properties of the grouting material and can effectively improve the rock mass’s hydraulic coupling characteristics. It also has great application value and practical significance for the prevention and control of water hazards in deep coal stopes.

Research on Static Compressive Experiment of Concrete Mixed with Limestone Power and Fly Ash

2013 ◽  
Vol 405-408 ◽  
pp. 2801-2805
Author(s):  
Ji Feng Liang ◽  
Lei Lv ◽  
Feng Wang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Test Method ◽  
Limestone Powder ◽  
Experimental Result ◽  
Enhancement Effect ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Orthogonal Test Method ◽  
Powder Content

The use of orthogonal test method, the concrete mixed with limestone power and fly ash was carried out static compressive experiment, and contrast with the experiment of single doped with limestone powder and fly ash concrete. The experimental result demonstrated that the compressive strength enhancement effect of the concrete mixed with limestone power and fly ash was obvious. The importance of each factor affecting static compressive strength as follows: water-cement ratio, the amount of fly ash, the amount of limestone powder, sand ratio. The concrete compressive strength reached the maximum when the water-cement ratio reached 0.3, the limestone powder content reached 15%, the fly ash content reached 10%, and sand ratio reached 34%.

Research on Mechanical Properties of Polymer Regenerative Concrete

2017 ◽  
Vol 873 ◽  
pp. 147-152
Author(s):  
Wei Liu ◽  
Shi Min Zhang ◽  
Hong Hao Ying ◽  
Nan Zhao
Keyword(s):  
Compressive Strength ◽  
Performance Test ◽  
Failure Process ◽  
Testing Machine ◽  
Concrete Block ◽  
Test Methods ◽  
Recycled Concrete ◽  
Ordinary Concrete ◽  
Strength Failure ◽  
Concrete Cube

This paper designed and completed the different polymer dosage of recycled concrete, was prepared by adding amount was 7%, 14%, 21%, 14% styrene butadiene latex recycled concrete, recycled rubber powder recycled concrete and ordinary concrete block, the cube compressive strength and damping performance test. The cube compressive strength of concrete test according to the ordinary concrete mechanics performance test methods, specimen is 150×150×150 mm cube specimens, pressure testing machine loading speed is 0.5 MPa per second. The concrete damping performance test is carried out according to the free attenuation method, with the hammer vibration test device, the test piece is T type. Based on the damage form of specimens, the compressive strength and damping performance analysis, and compared with ordinary concrete as the benchmark analysis test results show that the polymer recycled concrete cube compressive strength failure process and failure pattern basic consistent with common concrete; In the water/cement ratio, sand ratio, and amount of material per unit volume is the same, under the condition of polymer recycled concrete cube compressive strength is lower than normal concrete, damping performance is higher than that of ordinary concrete, the compressive strength is inversely proportional to the damping sexual relations.

scholarly journals Effects of Aluminum Sulfate and Quicklime/Fluorgypsum Ratio on the Properties of Calcium Sulfoaluminate (CSA) Cement-Based Double Liquid Grouting Materials

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1222 ◽  
Author(s):  
Yuli Wang ◽  
Jie Yu ◽  
Junjie Wang ◽  
Xuemao Guan
Keyword(s):  
Compressive Strength ◽  
Aluminum Sulfate ◽  
Setting Time ◽  
Strength Properties ◽  
X Ray Diffraction ◽  
Cement Slurry ◽  
Calcium Sulfoaluminate ◽  
Optimum Content ◽  
Grouting Material ◽  
Grouting Materials

Grouting materials are used frequently in grouting reinforcement projects, such as mining and coastal engineering. Double liquid grouting materials are mostly used because of the fast setting and high early strength properties when the two slurries are mixed together but high fluidity when the two slurries are separated. In our study, double liquid grouting materials were developed from CSA cement (slurry A), quicklime and fluorgypsum (slurry B). Aluminum sulfate was added in slurry B in order to counteract any adverse effects caused by the fluorgypsum, such as the decreased early compressive strength and the prolonged setting time. The effects of aluminum sulfate content and the quicklime/fluorgypsum ratio on the setting time, hydration heat, and compressive strength of the double liquid grouting materials were investigated, and the hydration products were characterized through thermogravimetry-differential thermal analysis (TG-DTA), X-ray Diffraction (XRD), and Scanning Electron Microscope (SEM) tests. The results show that the addition of aluminum sulfate can shorten the setting time and increase compressive strength at both early and later ages. Considering the setting time and compressive strength of double liquid grouting material at the same time, the optimum content of aluminum sulfate was found to be 2%, and the optimum ratio of quicklime/fluorgypsum was found to be 2:8. The values of the optimum content of aluminum sulfate and ratio of quicklime/fluorgypsum were verified from theoretical analysis.

scholarly journals The effect of nano-additive TiO2 on the failure process of self-compacting concrete assessed using the acoustic emission method

2018 ◽  
Vol 174 ◽  
pp. 02003
Author(s):  
Paweł Niewiadomski
Keyword(s):  
Acoustic Emission ◽  
Failure Process ◽  
Physical And Mechanical Properties ◽  
Test Method ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Emission Signal ◽  
Critical Stresses ◽  
Literature Reviews ◽  
The Impact

Due to the new challenges posed to engineering constructions, as well as the principles of sustainable development, many laboratories around the world are carrying out works to improve the basic structural material that is concrete. There has recently been a lot of interest in modifying concrete with nano-sized particles. Literature reviews indicate that their addition significantly improves the physical and mechanical properties of the concrete that was obtained with their use. Until now, there is no knowledge of the effect of nano-additives on the process of destroying temporarily compressed concrete. One test method that enables the parameters that describe the stress failure of concrete to be determined is the acoustic emission method. This work fills the gap in the literature and presents the results of the author's own research on the impact of the use of different amounts of nano-additive TiO2 on the failure process of selfcompacting concrete that was made solely on the basis of granite aggregate. The stress failure of the tested concrete was described using the stress levels (determined using the acoustic emission method) that initiate the cracking σi and critical stresses σcr that delimit the tested process. The descriptors that were used for this purpose are the rate of counts and the average effective value of the acoustic emission signal.

Researching on a New Grouting Material and its Engineering Application

2015 ◽  
Vol 1088 ◽  
pp. 544-548 ◽  
Author(s):  
Jing Lei Dou ◽  
Jing Feng Dou ◽  
Yu Juan Guo
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coal Mine ◽  
Engineering Application ◽  
The Body ◽  
Gas Explosion ◽  
Cement Material ◽  
Grouting Material ◽  
Grouting Materials

Water-irruption is the second to gas explosion of major security problems in coal mine. The grouting material is composed of fly ash and montmorillonite separately according to a certain proportion with pure cement material. On the site grouting test and compare the compressive strength of the stones of the body and the size of the diffusion radius, and compare the grouting materials with pure cement materials. Through the comparative and analysis, the reasonable grouting materials are choosen.

Study on Sintering Technology and Performance of Alite-Rich Cement Modified by C1.5Sr2.5A3S Mineral

2011 ◽  
Vol 306-307 ◽  
pp. 970-974
Author(s):  
Gui Qiang Li ◽  
Shou De Wang ◽  
Chao Nan Yin ◽  
Ling Chao Lu
Keyword(s):  
Compressive Strength ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Test Method ◽  
Cement Clinker ◽  
X Ray Diffraction ◽  
Sintering Time ◽  
Orthogonal Test Method ◽  
New Type ◽  
And Performance

The effects of the sintering temperature, sintering time and contents of calcium strontium suphoaluminate (C1.5Sr2.5A3) on the sintering technology of the alite-rich cement clinker modified by C1.5Sr2.5A3were researched by the orthogonal test method. X-ray diffraction, scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) and lithofacies analysis were used to investigate the compositions and structure of cement. The experimental results show that the optimal sintering temperature and sintering time of alite-rich cement clinker modified by C1.5Sr2.5A3are 1350 °C and 60 min, and the appropriate content of C1.5Sr2.5A3in the clinker is 2%. The introduction of C1.5Sr2.5A3in clinker can promote the formation of alite mineral at low temperature and decrease the sintering temperature of clinker by 100°C approximately. This new-type cement shows excellent mechanics properties. The compressive strength at 3d is up to 64.3MPa, which is increased by 26.7% comparing to that of alite-rich cement and the compressive strength at 28d is almost the same as that of alite-rich cement. For alite-rich cement clinker modified by C1.5Sr2.5A3calcinated at low temperature, alite still can be mass-formed, but the size decreases.

Sign in / Sign up

Export Citation Format

Share Document