Experimental Study on Groutability of Sand Layer concerning Permeation Grouting

Permeation grouting is widely used in grouting engineering because of its low grouting pressure and minor disturbance to the stratum. However, influenced by the complex properties of sand layer and slurry, an accurate prediction of the groutability of the sand layer remains to be a hard work. In this paper, the permeability of sand layer is studied based on a self-designed permeation grouting test device, which considers the different sand particle size, relative density of sand layer, slurry water-cement ratio, and clay content. The influencing factors of sand layer groutability are analyzed, and the different parameters that affect the grouting of sand layer are evaluated, thus proposing a new approach to predict the groutability of sand layer. Results show that the sand particle size and slurry water-cement ratio are positively related to the groutability of sand layer, and the relative density and clay content of sand layer are negatively correlated with the groutability of sand layer. The proposed alternative empirical formula to estimate the groutability of sand layer will help predict the groutability of sand layer with a higher degree of accuracy, which can provide a certain reference for engineering.

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Research on Influence of Water-Cement Ratio on Reinforcement Effect for Permeation Grouting in Sand Layer

Advances in Materials Science and Engineering ◽

10.1155/2020/5329627 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12 ◽

Cited By ~ 2

Author(s):

Zhipeng Li ◽

Lianzhen Zhang ◽

Yuntian Chu ◽

Qingsong Zhang

Keyword(s):

Deformation Modulus ◽

High Water ◽

Sand Layer ◽

Curing Time ◽

Reinforcement Effect ◽

Cement Slurry ◽

Permeation Grouting ◽

Cement Ratio ◽

Water Cement Ratio ◽

Grouting Reinforcement

In order to study permeation grouting reinforcement effect in the sand layer, a set of grouting test device is developed, which consists of a power device, a pressure-bearing slurry tank, and several test frames. Compressive strength, deformation modulus, and permeability coefficient are selected to be the evaluation index of grouting reinforcement effect. Grouting reinforcement effect under different water-cement ratio of cement slurry and curing time were measured. Eventually, under laboratory conditions, fitting formulas have been obtained which describe the quantitative relationship between reinforcement effect of permeation grouting and water-cement ratio and curing time. Results show that water-cement ratio of slurry has obvious effect on grouting reinforcement effect. Mechanical performance and impermeability of the grouted body are negative-correlated with water-cement ratio. There are two different destruction patterns for the grouted body in uniaxial compression process: global destruction pattern at low water-cement ratio and local destruction pattern at high water-cement ratio. If cement slurry at high water-cement ratio is permeated into the sand layer, water bleeding phenomena will appear and lead to inhomogeneous performance of the grouted body, with lower performance in the upper part and higher performance in the lower part of the grouted body.

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Test on Compaction Reinforcement Effect of Sand

Advances in Materials Science and Engineering ◽

10.1155/2020/3685619 ◽

2020 ◽

Vol 2020 ◽

pp. 1-17

Author(s):

Lianzhen Zhang ◽

Qingsong Zhang ◽

Zhipeng Li ◽

Hongbo Wang

Keyword(s):

Permeability Coefficient ◽

Clay Content ◽

Compression Modulus ◽

Sand Layer ◽

Reinforcement Effect ◽

Initial Water ◽

Grouting Pressure ◽

Performance Indexes ◽

The Relationship ◽

Water Ratio

In fracture or compaction grouting projects of sand layer, there exist many compacted sand regions on both sides of grout veins or around grout bulbs. It has an important effect on the final reinforcement effect of the sand layer that how much performance of the sand layer is improved after being compacted. Compression modulus, cohesion, and permeability coefficient are selected to be the performance indexes of the compaction reinforcement effect of sand. The relationship between the performance properties of sand and grouting pressure has been tested and analyzed. And influences of clay content and initial water ratio of sand on the compaction reinforcement effect have been studied. Results show that compaction can effectively improve the mechanical properties and impermeability properties of sand. Compression modulus of sand increases by 2∼18 times. The cohesion of sand increases from the scope of 9.4∼26 kPa to the scope of 40∼113.6 kPa. The permeability coefficient of sand decreases from the scope of 1.0 × 10−2∼ 8.33 × 10−4 cm/s to the scope of 2.19 × 10−4∼2.77 × 10−9 cm/s. When the clay content of sand is smaller than about 20%, sand cannot be reinforced effectively by compaction. Cohesion cannot be improved significantly and the permeability coefficient cannot be reduced markedly. A high initial water ratio of sand is beneficial to improve the compression modulus of compacted sand and goes against the improvement of cohesion of compacted sand. In addition, the initial water ratio has little effect on the permeability coefficient of compacted sand. In the end, fitting formulas have been developed to quantitatively describe the compaction reinforcement effect of sand by different grouting pressures.

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Experimental Investigation on the Law of Grout Diffusion in Fractured Porous Rock Mass and Its Application

Processes ◽

10.3390/pr6100191 ◽

2018 ◽

Vol 6 (10) ◽

pp. 191 ◽

Cited By ~ 1

Author(s):

Donghai Jiang ◽

Xianzhen Cheng ◽

Hengjie Luan ◽

Tongxu Wang ◽

Mingguang Zhang ◽

...

Keyword(s):

Rock Mass ◽

Permeability Coefficient ◽

Pressure Coefficient ◽

Porous Rock ◽

Cement Ratio ◽

Coal Resources ◽

Water Cement Ratio ◽

Grouting Pressure ◽

Study Results ◽

Residual Coal

Because of the limitation of mining techniques and economic conditions, large amounts of residual coal resources have been left in underground coal mines around the world. Currently, with mining technology gradually developing, residual coal can possibly be remined. However, when residual coal is remined, caving areas might form, which can seriously affect the safety of coal mining. Hence, grouting technology is put forward as one of the most effective technologies to solve this problem. To study the grouting diffusion in fractured rock mass, this paper developed a visualization platform of grouting diffusion and a three-dimensional grouting experimental system that can monitor the grout diffusion range, diffusion time and grout pressure; then, a grouting experiment is conducted based on this system. After that, the pattern of the grouting pressure variation, grout flow and grout diffusion surface are analyzed. The relationship among some factors, such as the grouting diffusion radius, compressive strength of the grouted gravel, porosity, water-cement ratio, grouting pressure, grouting time, permeability coefficient and level of grout, is quantitatively analyzed by using MATLAB. The study results show that the flow pattern of the grout in fractured porous rock mass has a parabolic shape from the grouting hole to the bottom. The lower the level is, the larger the diffusion range of the grout is. The grouting pressure has the greatest influence on the grouting diffusion radius, followed by the grouting horizon and water-cement ratio. The grouting permeability coefficient has the least influence on the grouting diffusion radius. The grout water-cement ratio has the greatest influence on the strength of the grouted gravel, followed by the grouting permeability. The grouting pressure coefficient has the least amount of influence on the grouting diffusion radius. According to the results, the grouting parameters are designed, and a layered progressive grouting method is proposed. Finally, borehole observation and a core mechanical property test are conducted to verify the application effect. This grouting technology can contribute to the redevelopment and efficient utilization of wasted underground coal resources.

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Experimental Study on Diffusion Law of Post-Grouting Slurry in Sandy Soil

Advances in Civil Engineering ◽

10.1155/2019/3493942 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Jianyu Yang ◽

Yanhui Cheng ◽

Weichao Chen

Keyword(s):

Permeability Coefficient ◽

Cement Slurry ◽

Cement Ratio ◽

Water Cement Ratio ◽

Grouting Pressure ◽

Empirical Function ◽

Pressure Water ◽

Post Grouting ◽

Function Relationship ◽

Experimental Reference

In order to study the diffusion law of grouting slurry in sand areas, the grouting of cement slurry in sand was analyzed by the indoor grouting test under different water-cement ratios, grouting pressures, grouting amounts, and soil qualities, and the law of the post-grouting slurry is obtained. The results show that the grouting method is affected by the grouting pressure, water-cement ratio, grouting amount, and soil quality. Under the same grouting pressure, the diffusion modes of different water-cement ratio grouts in sands with different permeability coefficients, which are mainly manifested as osmotic diffusion, are basically the same; under the same water-cement ratio, when the grouting pressure is relatively small, the diffusion of modes of slurry is mainly osmotic in sand. The diffusion radius of cement slurry in sand has a good power function relationship with grouting pressure, water-cement ratio, permeability coefficient, and grouting amount. And, the empirical function model of slurry diffusion radius is proposed by regression analysis. The research results provide a certain theoretical and experimental reference for post-grouting in sandy areas.

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Eco-efficient earth plasters: influence of clay content, sand particle size and support

Journal of World Architecture ◽

10.26689/jwa.v2i6.634 ◽

2018 ◽

Vol 2 (6) ◽

Cited By ~ 1

Author(s):

TÃ¢nia Santos ◽

M. IdÃ¡lia Gomes ◽

FlÃ¡via Coelho ◽

Paulina Faria

Keyword(s):

Particle Size ◽

Surface Hardness ◽

Clay Content ◽

Fine Sand ◽

High Mass ◽

Sand Particle ◽

Visual Appearance ◽

Earth Construction ◽

High Mass Loss ◽

Efficient Construction

Earth construction, including the use of earth mortars, has been extensively used in the past. However, with the appearance of hydraulic binders, the use of earth strongly decreased for new construction and even to repair old earth buildings, whose best solution would be the use of compatible materials such as earth mortars.Due to the innumerable advantages of earth and with the growing concern on eco-efficient construction, the interest on earth construction has resurfaced, namely on earth mortars.In order to optimize the composition of an earth plastering mortar made with a defined clayish earth and two siliceous sands with different particle size, six compositions were assessed. Mortars with different volumetric ratios were applied in two different supports (on the back of a tile and on a brick) and planar specimens were also produced. Distinct characteristics were assessed, such as their visual appearance, shrinkage, surface cohesion, surface hardness, dry abrasion resistance, ultrasonic velocity, adhesive strength and thermal conductivity.It is possible to conclude that a higher clay content in the earth mortar composition increases the shrinkage and occurrence of cracking, the use of fine sand promotes high mass loss by abrasion, and the same mortar applied in different supports behave differently in terms of durability.

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Water Requirement of Concrete with Mineral Admixtures

International Journal for Research in Applied Science and Engineering Technology ◽

10.22214/ijraset.2021.36021 ◽

2021 ◽

Vol 9 (VI) ◽

pp. 4573-4577

Author(s):

Alka A. Avasthi

Keyword(s):

Particle Size ◽

Water Content ◽

Surface Area ◽

Agricultural Waste ◽

Water Requirement ◽

Mineral Admixtures ◽

Partial Replacement ◽

Cement Ratio ◽

Water Cement Ratio ◽

Cement Replacement

India is one of the leading producers of sugar and rice, hence agricultural waste is generated in huge quantities in India leading to potential disposal problems without effective management techniques. However, the economic importance of this solid waste has been realised with several applications like adsorbents, filters, ceramics, briquettes, bricks, and blocks and soil amendment activities. Cement is one of the most universally used material. Cement production is an environmental threat as well as the production cost is also very high. Manufacturing of cement and its use is also one of the causes of global warming Environmentalists and Researchers around the world are searching for better options to replace cement As cement replacement materials mineral admixtures are nowadays gaining mileage as they address two problems. First is the waste management of agricultural wastes, which causes air pollution due to open air burning and the second is reducing the demand for cement. Hence in addition to reducing the cost it also reduces the hazardous effect that it has on the environment. In general, the particle size of these admixtures play an important role in making the concrete dense, but low particle size leads to increased surface area and more requirement their surface area increases and workability reduces. Hence to make the concrete workable the water requirement also increase [1].Generally the water requirement or the water cement ratio for normal concrete is between 0.35 to 0.5 , depending on the cement content and the mix design . For high strength concrete where the quantity of cement increases the water cement ratio also increases. But in concrete with mineral admixtures the water cement ratio is more than 0.6. The present paper deals with the water requirement for the concrete with cement replacement with mineral admixtures , The two types of admixtures water requirement of concrete with partial replacement of cement with sugarcane bagasse ash and rice husk ash in different proportions of 5 % , 10%, 15% , 20%, 25% and 30 % , earlier as a binary mix replacing the mineral admixtures individually and later together as a ternary mix using both the mineral admixtures together. The results indicate increase in water content with the increase in cement replacement proportions in both the binary and ternary mix . The increase in water content does not hamper the compressive strength of the binary and ternary mix , but in some cases increases it.

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Performance of Cement Bonded Particleboards Made from Grapevine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.631-632.765 ◽

2013 ◽

Vol 631-632 ◽

pp. 765-770

Author(s):

Chuan Gui Wang ◽

Shuan Gyan Zhang ◽

Heng Wu

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Particle Size ◽

Internal Bond ◽

Physical And Mechanical Properties ◽

Modulus Of Rupture ◽

Thickness Swelling ◽

Cement Ratio ◽

Water Cement Ratio ◽

Effect Of Particle Size

Cement bonded particleboards were manufactured form grapevine stalk particles. The physical and mechanical properties of the boards were assessed. Results revealed that the mixture of grapevine-cement for either treatment of particles, was graded as “low inhibition” when CaCl2 was incorporated, as determined by the hydration tests. Three factors namely grapevine-cement ratio, water-cement ratio and particle size were applied in this study for the board manufacturing. Increase in grapevine-cement ratio caused decrease in Modulus of rupture (MOR), Modulus of elasticity (MOE), Internal bond (IB), thermal conductivity and increase in Thickness swelling (TS). Increase in water-cement ratio caused decrease in MOR, MOE, IB, TS and thermal conductivity. The particle size resulted in little change in all, but TS. The MOR, MOE, IB of the boards were significantly affected by grapevine-cement and water-cement ratios except for TS. Only the effect of particle size on thermal conductivity is significant at 0.05 level significance.

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Influence of Water-Cement Ratio on Viscosity Variation of Cement Grout in Permeation Grouting

Geofluids ◽

10.1155/2021/7126013 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Gaohang Lv ◽

Jian Liu ◽

Bo Han ◽

Tiantao Zhang ◽

Quanyi Xie ◽

...

Keyword(s):

Relative Error ◽

Apparent Viscosity ◽

Cement Grout ◽

Time Dependent ◽

Permeation Grouting ◽

Cement Ratio ◽

Water Cement Ratio ◽

Dependent Behavior ◽

Viscosity Variation ◽

Cement Grouts

Diffusion radius is an important construction parameter, because it can significantly influence the grouting effectiveness. Theoretical models in predicting diffusion radius have been practiced, but there are still significant discrepancies between theoretical calculations and realistic results in the practical construction. One of the critical reasons for the misprediction is the time-dependent behavior of the cement grout, which is significantly affected by the water-cement ratio (W/C). Therefore, this paper experimentally and numerically studies the influence of W/C on the viscosity variation of the grout and grouting process. Firstly, the apparent viscosity of the cement grout under different W/C is tested by a rotational viscometer in a laboratory experiment. Subsequently, based on the laboratory tests, numerical models are established to investigate the influence of W/C on the diffusion process of cement grout in sand layers. According to the laboratory results, the apparent viscosity of cement grouts decreases with the increase of W/C. Besides, the apparent viscosity increases with time, while the increasing range of apparent viscosity firstly increases and then decreases as W/C increases. Based on the simulated results, when W/C changes from 0.8 to 1.1, the diffusion radius at 60 min experiences a less and less obvious increase under the given grouting pressure for permeation grouting in the sand layer. When W/C is 0.9, the relative error reaches to 37.65% at 60 min, which is slightly lower than that of 0.8. However, when W/C changes from 0.9 to 1.0, the relative error becomes very narrow (21.36%), and this figure is much lower than that of 0.8 or 0.9. The simulation results are verified by field test, and the relative error is 6%, which proves the effectiveness of the analysis. Therefore, the cement permeation model considering viscosity variation of the grout is a reasonable alternative in the real project. At the same time, the time-dependent behavior of cement grouts should be considered, especially when using cement grouts with a low water-cement ratio in the practical engineering.

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Cement Slurry Plugging Law and Optimal Plugging Flow Rate at a High Hydraulic Gradient

Advances in Civil Engineering ◽

10.1155/2021/6696229 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Peili Su ◽

Yifei Jia ◽

Feng Liu ◽

Chong Li

Keyword(s):

Theoretical Model ◽

Flow Rate ◽

Hydraulic Gradient ◽

Model Verification ◽

Cement Slurry ◽

Cement Ratio ◽

Water Cement Ratio ◽

Grouting Pressure ◽

Deposition Thickness ◽

Velocity Water

With the continuous development of coal and rock mass engineering, water inrush grouting has become an urgent problem in engineering disaster management. Herein, a theoretical model of the optimal plugging flow rate was established, and a comparative theoretical analysis was performed based on the results of indoor model tests. The particle incipient velocity was defined as the optimal plugging flow rate. The effects of hydrodynamic velocity, water-cement ratio, grouting pressure, and fracture aperture on the cement slurry grouting plugging were studied, and the optimal threshold of the plugging flow rate was obtained for theoretical model verification. Results showed that, at a high hydraulic gradient, the plugging effect of the grout was mainly affected by the hydrodynamic velocity, water-cement ratio, and grouting pressure (listed in the order of importance). When the hydrodynamic velocity was low, the difference in the slurry deposition thickness was large under different water–cement ratios and pipe diameters. When the hydrodynamic velocity was increased, the influence of various factors on the slurry deposition thickness decreased. Through a comparative analysis of the experimental and theoretical values, the optimal plugging velocity of pure cement slurry was 0.5–0.55 m·s−1 under different conditions, and the error between the experimental and theoretical values was less than 0.1 m·s−1, which confirmed the rationality of the proposed model.

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