Papers by Keyword: Grouting

Abstract: A mayor problem in bridge engineering is the insufficient knowledge concerning the condition of prestressing reinforcement, especially in prefabricated bridge girders, which is largely related to the measure of grouting of cable duct. Therefore, this article deals with non-destructive methods that could verify the filling of cable duct with grout along their entire length, not just randomly in a few selected places. That is why it was decided to use modern non-destructive devices like GPR Live (8000), HILTI PS 1000 and Pundit 250 Array.

Abstract: Many methods have been used for soil improvement at site, one of these methods is grouting. Cement grouted soils consist of particulate soil media and cementation agents. Such soils have been widely used to improve the shear strength and stiffness of weak soils and for preventing of water seepage through soils. The modulus of subgrade reaction may give a good indication about the soil bearing capacity and stiffness. This geotechnical parameter can be measured by using the plate load test. In this study, an experimental work is done to assess the improvement in the stiffness of sandy soils by injection two different cementing agents (cement and colloidal silica). The work includes plate loading tests with two different plate diameters (B= 150 and B= 250 mm). The effects of plate size, depth of the grouted zone (0-B and B-2B) as well as the effect of grouting material type on the performance of the grouted soil are investigated. The results show that the colloidal silica grout is more effective in increasing the modulus of sub grade reaction (k_s) than the cement grout. Also, the use of plate with 150 mm diameter gives higher value of (k_s) than that of 250 mm diameter. Furthermore, grout injection at depth (from 0 to B) gives a higher value of (k_s) than that for deeper grouted zone.

Abstract: The publication reviews recent applications of 172nm excimer radiation in bio-electric fields. It shows the broad field which already profit from the technology and also illustrates possible potentials. The principle of erasing static electricity from polyimide surfaces is explained as one application. The effect as a function of the dose is presented both for positive and negative charge and typical materials.In addition the VUV cleaning mechanism with 172nm excimer radiation is demonstrated by the mass spectroscopy of contaminations on the surface of a Si wafer.Surface energy changes of polyamides, glass and metal as a function of dose are presented as well as the change of the contact angle of water on the surface.Another application of surface energy enhancement is the polymer microchip production. Due to the surface activation, the bonding strength for the PMMA-Si combination is significantly enhanced. The results are presented in comparison to other surface treatment methods.Another presented application which profits from the surface activation is adhesive-free coupling. The mechanism of this application is explained and the adhesion strength as a function of material combination is presented. For 2 typical applications, the bonding strength is shown as a function of applied dose. A glance at other applications and an outlook is given as well.

Abstract: In some tunnels of railway lines located in water-rich region, due to the long-term water leakage and erosion, the foundation of railway lines showed large uneven settlement deformation, so the above concrete roadbed slabs also experienced uneven settlement accordingly. The smoothness of railway tracks diminished, and the speed of passing trains had to be limited to ensure safety. To restore the smoothness of the tracks, a dedicated polymer injection technology for quick uplift rehabilitation of uneven settlement concrete roadbed slabs was studied on site just within the specified daily skylight time (about 3 hours every day) of the railway lines. A hydrophobic polymer with low-viscosity, quick-setting and high-strength properties was used for injecting, filling and uplifting the concrete slabs in water-rich foundations. The high-precision electronic levels were adopted to monitor rising height of the tracks in real time. After rehabilitation, the filling quality of polymer injection under roadbed slabs was examined using Φ50 mm core samples and the strength of hardened polymer was verified by compressive strength test. Results indicated that the polymer could uplift the concrete roadbed slabs effectively and restore the smoothness of railway tracks accurately even in the water-rich environment. The research can provide some valuable references for quick rehabilitation of uneven settlement concrete roadbed slabs in water-rich tunnels.

Abstract: Liquefying is an effort to achieve the lowest viscosity at the lowest water content in the mixture. Low water content tends to increase manipulation strength, and consequently to improve the physical and mechanical properties of the resulting mixture after hardening. The aim of this paper is to verify the influence of liquefying additives, namely, sodium hexametaphosphate and tripolyphosphate on properties of clay-fly ash grouting mixtures. Tested properties of these mixtures are viscosity, additional shrinkage, coefficient of filtration and compressive strength.

Abstract: Improving properties of materials is an integral part of almost of all remedial interventions; one of the most challenging remediation is the remediation of damp masonry. With the development of advanced technologies in the field of remedial chemicals there is one of the increasingly used methods – the method of high-pressure chemical grouting. Its use, however, raises the question how to control the quality of the design. This article deals with the possibility of mathematical modeling of grouting design of damp masonry and using the indirect method based on infrared radiation for subsequent checks.

Abstract: Based on the discussion of beneath cement concrete pavement void disease, the slab bottom grouting is the main method to solve the disease, and also discussing the strength, frost resistance, resistance to shrinkage, flow uniformity, grouting construction points and ratio of grouting materials, the key points of construction quality control of grouting are specified, the cement pavement disease treatments are put forward.

Abstract: This paper mainly introduced the grouting reinforced governance issues of old goaf of which exist building on the surface. Combined with the engineering example, the use of GTS software to identify mined areas and the the drilling histogram to establish three-dimensional geological model of gob region. Put forward to carry out positioning quantitative grouting technology on the goaf according to three-dimensional geological model, and strengthen the gob by using grouting method.

Abstract: The accumulated CaO consumption rate of 25% in grouting concretion stone is considered as the termination of durability life in the paper. Influence factors on the service life of grouting cement stone are studied and the variation laws on the service life, strength and pH value are revealed. The acceptance criteria of durability evaluation are proposed. The practical methods for durability evaluation are established based on the pH value of caustic solution including the expression of service life prediction model, and classification principles of durability evaluation. The calculation process is illustrated by examples. The method provides references for the durability evaluation of grouting concretion stone under the common atmosphere.

Abstract: Based on a roadway project of Dongqu Colliery of Xishan Coal and Electricity Group,using the geological exploration data and on-site research and referring to the theory and engineering experience, the tunnel grouting program for marl was worked out and it was revised the program in the construction. A method of grouting for soft rock in roadway construction was summarized ,getting a good results and verified by numerical simulation.