scholarly journals Concrete properties in diaphragm walls embedded in non-cohesive soils

2018 ◽  
Vol 174 ◽  
pp. 01007 ◽  
Author(s):  
Magdalena Czopowska-Lewandowicz
Keyword(s):  
Diffraction Method ◽  
Physical And Mechanical Properties ◽  
Diaphragm Wall ◽  
Concrete Mixture ◽  
Cohesive Soils ◽  
Existing Building ◽  
Concrete Quality ◽  
Diaphragm Walls ◽  
Bentonite Suspension ◽  
The Impact

Although diaphragm walls are massive and responsible structures whose building history has many years' tradition, the discovery of a variety of material faults is still common throughout their exploitation. Some of the most common ones are associated with the occurrence of leaks along the wall surface. This paper reports on the results of a study conducted into concrete quality in an existing building structure. The issues identified in this case include the potential penetration of groundwater and particles suspended in non-cohesive soils into the bentonite suspension and into the concrete mixture. The scope of the analysis also involved the possible occurrence of a mixing zone of bentonite suspension with the concrete mixture. The solutions presented in this paper were practically tested using an existing structure and the results confirm that the adopted approach needs to be thoroughly researched. The laboratory specimens derived from an unreinforced diaphragm wall were subjected to the following tests: concrete bulk density in the air-dried state, water absorption by concrete, depth of water penetration under pressure, compressive strength and determination of the quantitative phase composition test using X-ray diffraction method. The results clearly demonstrate the decrease of the concrete quality applied in a monolithic diaphragm wall in comparison to the reference samples taken at the phase when it was built. Due to the fact that it was impossible to identify the impact of the particular variables on the investigated structure, this paper focuses on their descriptive assessment. This discussion is based on the analysis of the results defining the physical and mechanical properties of the examined concrete coupled with observations made by the author and insights derived from literature.

scholarly journals Estimation of physical and mechanical properties of cohesive soil stabilized by hydratized lime addition

2013 ◽  
Vol 45 (2) ◽  
Author(s):  
Wojciech Sas ◽  
Andrzej Głuchowski ◽  
Jarosław Margielski
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Cohesive Soil ◽  
Hydrated Lime ◽  
Chemical Stabilization ◽  
Cohesive Soils ◽  
Silty Clay ◽  
Cbr Test ◽  
The Impact ◽  
Lime Addition

AbstractEstimation of physical and mechanical properties of cohesive soil stabilized by hydratized lime addition. Process of chemical stabilization of cohesive soils influences its mechanical properties, also in the case of soil cohesion. Road constructions consist of few layers which have various mechanical properties and this creates the need for better understanding the impact of chemical stabilization on soil as a layer of road. For the purposes of this article, tests were carried out in order to establish physical and mechanical properties, especially the penetrating resistance CBR test. The main aim of this paper was to estimate the cohesion of the soil, which was sandy-silty clay stabilized with hydrated lime

Assessment of Diaphragm Wall's Structural Impact on Groundwater Hydrology

2011 ◽  
Vol 250-253 ◽  
pp. 1098-1104
Author(s):  
Te Hsing Chang
Keyword(s):  
Groundwater Level ◽  
High Speed ◽  
Vibration Reduction ◽  
High Water ◽  
Diaphragm Wall ◽  
Wall Structure ◽  
Groundwater Hydrology ◽  
Groundwater Levels ◽  
Diaphragm Walls ◽  
The Impact

The Southern Taiwan Science Park (STSP) is located between Hsinshi Township and Shanhua Township of Tainan County, with the newly-built, high-speed railway running through its eastern side. The low-frequency vibration which was generated by passing high-speed trains causes environmental disturbances to industries within the Park. To address this issue, the implementation of vibration-reduction project with detailed design and construction was provided. The diaphragm wall-type vibration reduction walls will be built along the borderline between Hsinshi Township and Shanhua Township to reduce the impact on industries. The diaphragm wall structure will block groundwater from flowing to affect the underground hydrology. This study was aimed to discuss and assess the best configuration for the vibration reduction effects and environmental impacts. Numerical analysis of the impacts on groundwater hydrology was conducted in two cases. The simulation results indicated that both sides of diaphragm walls developed gaps in groundwater levels. Hence, diaphragm walls effectively reduced adverse impacts on groundwater hydrology with openings at locations where underground pipelines ran. Such variations were within the scope of groundwater level of high water and low water periods. Therefore, surface runoff and land subsidence resulting from the diaphragm wall construction were not severe. As diaphragm walls were made of impermeable materials, pumping water nearby made the groundwater level drawdown effects worse. Groundwater level variations resulting from pumping water were far greater than the regional groundwater level variations after the establishment of diaphragm walls. Special attention must be paid to this situation in follow-up management.

scholarly journals Damage Evolution of Granodiorite after Heating and Cooling Treatments

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 779
Author(s):  
Mohamed Gomah ◽  
Guichen Li ◽  
Salah Bader ◽  
Mohamed Elkarmoty ◽  
Mohamed Ismael
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Failure Mode ◽  
Physical And Mechanical Properties ◽  
P Wave ◽  
Physical Parameters ◽  
Slow Cooling ◽  
Heating And Cooling ◽  
Natural Rock ◽  
The Impact

The awareness of the impact of high temperatures on rock properties is essential to the design of deep geotechnical applications. The purpose of this research is to assess the influence of heating and cooling treatments on the physical and mechanical properties of Egyptian granodiorite as a degrading factor. The samples were heated to various temperatures (200, 400, 600, and 800 °C) and then cooled at different rates, either slowly cooled in the oven and air or quickly cooled in water. The porosity, water absorption, P-wave velocity, tensile strength, failure mode, and associated microstructural alterations due to thermal effect have been studied. The study revealed that the granodiorite has a slight drop in tensile strength, up to 400 °C, for slow cooling routes and that most of the physical attributes are comparable to natural rock. Despite this, granodiorite thermal deterioration is substantially higher for quick cooling than for slow cooling. Between 400:600 °C is ‘the transitional stage’, where the physical and mechanical characteristics degraded exponentially for all cooling pathways. Independent of the cooling method, the granodiorite showed a ductile failure mode associated with reduced peak tensile strengths. Additionally, the microstructure altered from predominantly intergranular cracking to more trans-granular cracking at 600 °C. The integrity of the granodiorite structure was compromised at 800 °C, the physical parameters deteriorated, and the rock tensile strength was negligible. In this research, the temperatures of 400, 600, and 800 °C were remarked to be typical of three divergent phases of granodiorite mechanical and physical properties evolution. Furthermore, 400 °C could be considered as the threshold limit for Egyptian granodiorite physical and mechanical properties for typical thermal underground applications.

A Method for Evaluating Intensity of Water Cavitation Peening Processing

2011 ◽  
Vol 675-677 ◽  
pp. 747-750
Author(s):  
B. Han ◽  
Dong Ying Ju ◽  
Xiao Guang Yu
Keyword(s):  
Residual Stress ◽  
Process Capability ◽  
Diffraction Method ◽  
Spring Steel ◽  
Bubble Collapse ◽  
Plastic Layer ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
Near Surface ◽  
The Impact

Water cavitation peening (WCP) with aeration, namely, a new ventilation nozzle with aeration is adopted to improve the process capability of WCP by increasing the impact pressure induced by the bubble collapse on the surface of components. In this study, in order to investigate the process capability of the WCP with aeration a standard N-type almen strips of spring steel SAE 1070 was treated byWCP with various process conditions, and the arc height value and the residual stress in the superficial layers were measured by means of the Almen-scale and X-ray diffraction method, respectively. The optimal fluxes of aeration and the optimal standoff distances were achieved. The maximum of arc height value reach around 150μm. The depth of plastic layer observed from the results of residual stresses is up to 150μm. The results verify the existence of macro-plastic strain in WCP processing. The distributions of residual stress in near-surface under different peening intensity can provide a reference for engineers to decide the optimal process conditions of WCP processing.

Study on Techniques for Rapidly Testing the Composition of Concrete Mixture

2013 ◽  
Vol 838-841 ◽  
pp. 30-35
Author(s):  
Xiao Bin Sun ◽  
Tian Ling Du ◽  
Bo Tian
Keyword(s):  
Quality Control ◽  
Laboratory Test ◽  
Rapid Detection ◽  
Measurement Accuracy ◽  
Fresh Concrete ◽  
Concrete Mixture ◽  
Quality Problem ◽  
Detection Techniques ◽  
Concrete Quality ◽  
Practical Engineering

With regards to the quality problem of concrete that cant be found out earlier in the quality control, this paper discussed the principle to rapidly detect composition of concrete mixture and analyzed the measurement accuracy of water checker for fresh concrete through laboratory test. Experiments showed that the error in unit cement and unit water measured by instruments is relatively small and able to meet the accuracy requirements. And, the application of rapid detection techniques to the concrete quality control in practical engineering has achieved good results.

Effects of Loading Percentage of Polyurethane in Lightweight Concrete

2013 ◽  
Vol 357-360 ◽  
pp. 1082-1085 ◽  
Author(s):  
Kamarul Aini Mohd Sari ◽  
Sohif Mat ◽  
Khairiah Haji Badri ◽  
Muhammad Fauzi Mohd Zain
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Lightweight Concrete ◽  
Palm Kernel ◽  
Physical And Mechanical Properties ◽  
Concrete Mixture ◽  
Experimental Program ◽  
Polymer Concrete ◽  
Optimum Level ◽  
Methylene Diphenyl Diisocyanate

An experimental program was performed to obtain the density, compressive strength, and thermal conductivity of palm-based lightweight concrete. Palm-based polyurethane (PU) particles were used as lightweight aggregates in creating concrete systems. Concrete systems contain palm kernel oil-based polyol (PKO-p) reacted with 2,4-methylene diphenyl diisocyanate (MDI). In this study, polymer concrete was improved to achieve the optimum level of PU with the lowest possible density. The PU particles in the concrete mixture comprised of 1% to 5% w/w with density of less than 1800 kg/m3. The PU particles were 5 mm in size. The ratio of PKO-p to MDI was set at 1:1 and the loading of the concrete mixture was set at 3% w/w to produce lightweight concrete. The resulting concrete has excellent compressive strength (17.5 MPa) and thermal conductivity (0.24 W/mK). Results show that the PU particle dosage has the most significant effect on the physical and mechanical properties of concrete.

scholarly journals The Effect of the Morphology of Coarse Aggregate on the Properties of Self-Compacting High-Performance Fibre-Reinforced Concrete

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1372 ◽  
Author(s):  
Krzysztof Ostrowski ◽  
Łukasz Sadowski ◽  
Damian Stefaniuk ◽  
Daniel Wałach ◽  
Tomasz Gawenda ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Coarse Aggregate ◽  
Fresh Concrete ◽  
Physical And Mechanical Properties ◽  
Concrete Mixture ◽  
Rheological Parameters ◽  
Transverse Strain ◽  
Fibre Reinforced Concrete ◽  
High Performance Fibre

When understanding the effect of the morphology of coarse aggregate on the properties of a fresh concrete mixture, the strength and deformability of self-compacting high-performance fibre-reinforced concrete (SCHPFRC) can be seen to be critical for its performance. In this research, regular and irregular grains were separated from granite coarse aggregate. The morphology of these grains was described while using digital image analysis. As a result, the aspect ratio, roundness and area ratio were determined in order to better understand this phenomenon. Then, the principal rheological, physical, and mechanical properties of SCHPFRC were determined. The obtained results indicated that the morphology of the grains of coarse aggregate has an impact on the strength and stiffness properties of SCHPFRC. Moreover, significant differences in the transverse strain of concretes were observed. The morphology of the coarse aggregate also has an impact on the rheological parameters of a fresh concrete mixture. To better understand this phenomenon, the hypothesized mechanism of the formation of SCHPFRC caused by different morphology of coarse aggregate was proposed at the end of the article.

scholarly journals Effect of microwave disinfection on physical and mechanical properties of acrylic resins

2008 ◽  
Vol 19 (4) ◽  
pp. 348-353 ◽  
Author(s):  
Rafael Leonardo Xediek Consant ◽  
Erica Brenoe Vieira ◽  
Marcelo Ferraz Mesquita ◽  
Wilson Batista Mendes ◽  
João Neudenir Arioli-Filho
Keyword(s):  
Flexural Strength ◽  
Room Temperature ◽  
Physical And Mechanical Properties ◽  
Hardness Test ◽  
Knoop Hardness ◽  
Microwave Energy ◽  
Bending Test ◽  
Acrylic Resins ◽  
Strength Tests ◽  
The Impact

This study evaluated the effect of microwave energy on the hardness, impact strength and flexural strength of the Clássico, Onda-Cryl and QC-20 acrylic resins. Aluminum die were embedded in metallic or plastic flasks with type III dental stone, in accordance with the traditional packing technique. A mixing powder/liquid ratio was used according to the manufacturer's instructions. After polymerization in water batch at 74ºC for 9 h, boiling water for 20 min or microwave energy at 900 W for 10 min, the specimens were deflasked after flask cooling at room temperature, and submitted to finishing. Specimens non-disinfected and disinfected by microwave irradiation were submitted to hardness, impact and flexural strength tests. Each specimen was immersed in distilled water and disinfected in a microwave oven calibrated to 650 W for 3 min. Knoop hardness test was performed with 25 g load for 10 s, impact test was carried out using the Charpy system with 40 kpcm, and 3-point bending test with a crosshead speed of 0.5 mm/min until fracture. Data were submitted to statistical analysis by ANOVA and Tukey's test (?=0.05). Disinfection by microwave energy decreased the hardness of Clássico and Onda-Cryl acrylic resins, but no effect was observed on the impact and flexural strength of all tested resins.

scholarly journals Pengaruh Penambahan Limbah Plastik Jenis Thermosetting Terhadap Parameter Marshall Laston AC-WC

2019 ◽  
Vol 24 (2) ◽  
pp. 166
Author(s):  
Kusdiyono Kusdiyono ◽  
Supriyadi Supriyadi ◽  
Tedjo Mulyono ◽  
Sukoyo Sukoyo
Keyword(s):  
Asphalt Concrete ◽  
Plastic Waste ◽  
Concrete Mixture ◽  
Partial Replacement ◽  
Short Term ◽  
Road Pavement ◽  
Long Run ◽  
Plastic Bag ◽  
Marshall Stability ◽  
The Impact

At present, plastic is a material that is needed by the community at large, where the impact is also very extraordinary after the plastic is used in everyday life which can cause serious problems if the management is not done properly. The problem of plastic waste does not only occur in the city of Semarang, but also in other cities, so that the Ministry of Environment and Forestry has implemented a paid plastic bag program in the short term. But this is only to deal with problems in the short term. In the long run, it will not solve the problem of "plastic waste", because the policy actually encourages people to buy plastic which, of course, will add a new burden for the community to buy it. Based on the above problems, it is necessary to utilize this plastic waste to be made into road pavement materials such as in the manufacture of Asphal Concrette Wearing Course, by making 5 mixed variations ranging from (2 to 10)% of the weight of the aggregate . This research was initiated through a survey process, material procurement, testing of stacking materials, making test specimens, testing specimens. The results of the research can show that the type of Thermosetting plastic waste has a significant influence on the Asphalt Concrete mixture AC-WC heat mixture, including: Density, Marshall Stability, Flow, VIM, VMA, MQ and the remaining Marshall Stability tend to show an increase, moderate VFA and VIMrefusal Density values tend to show a decrease. Thus the plastic waste from the Thermosetting type can be used as a partial replacement of the aggregate for the Asphalt Concrete mixture AC-WC heat mixture with a plastic waste content is limited to a maximum of 10% and at an optimum asphalt content of 5.55%. Thus this research is expected to be of benefit to the industry and the people of Semarang in relation to the use of plastic waste for road pavement.

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