scholarly journals Improving the safety of railway subgrade when it is strengthened using soil-cement elements

2019 ◽  
Vol 294 ◽  
pp. 03006
Author(s):  
Vitalii Krysan ◽  
Volodymyr Krysan ◽  
Volodymyr Petrenko ◽  
Oleksii Tiutkin ◽  
Volodymyr Andrieiev
Keyword(s):  
Cement Content ◽  
Laboratory Studies ◽  
Weak Soil ◽  
Civil Structures ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Soil Cement ◽  
Access Road ◽  
The Difference

The article identifies the main parameters of the drilling-mixing technology, which is the most effective in fixing weak soil bases during the construction and restoration of transport, industrial and civil structures. The difference of the technology developed by the authors is that the strengthening process is carried out at low pressure (0.15 ... 0.25 MPa). The relevance of the research is that the proposed technology requires less cost with high rates of restoring the strength of soil foundations. To prove the high quality of the technology, laboratory studies were carried out to determine the optimal characteristics of the soil-cement element, as well as the proportions and composition of the fixing solution. The dependences of the strength of soil-cement elements in the air-dry condition with cement content from 7% to 23% with water-cement ratio in solution 1 / 0.3 and with cement content from 13% to 37.5% with water-cement ratio in solution 1/0,6. During the experimental-industrial studies of the author’s technology, the embankment was constructed with the soil-cement-reinforced elements for the access road approaches at one of the facilities in Kirovograd region, which ensured safety in the operation of a complex transport structure.

The Quest for Absolute Concrete Durability Performance Criteria

2016 ◽  
Vol 711 ◽  
pp. 599-606
Author(s):  
Geert de Schutter
Keyword(s):  
Cement Content ◽  
Performance Criteria ◽  
Concrete Durability ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
The Real ◽  
Binder Type ◽  
Maximum Water ◽  
Standard Solution ◽  
Durability Performance

Deemed-to-satisfy durability requirements, as typically provided in code prescriptions (minimum cement content, maximum water cement ratio, minimum strength class) are now approaching their limits of applicability. With the implementation of new tailor-made binder types, including a multitude of powders (reactive and even non-reactive), the prescriptive parameters cement content and water/cement ratio become unclear and do not always correlate well with the real durability performance. While the equivalent concrete performance concept (ECPC) already offers a first way out of this debate, it still fundamentally maintains durability requirements at a deemed-to-satisfy level, as the new binder type needs to be experimentally calibrated relative to a standard solution. A more fundamental solution needs to consider the absolute durability performance of the concrete applied in the real structure. This performance needs to be evaluated in laboratory conditions (potential performance) as well as on the final structure (as-built performance). However, although straightforward in principle, the quest for absolute durability performance criteria is complicated, with remaining fundamental obstacles. This paper intends to give a general overview.

Study of Sleeper Concrete early Strength Based on Orthogonal Experiment

2013 ◽  
Vol 448-453 ◽  
pp. 1316-1320
Author(s):  
Hai Chao Wang ◽  
Ke Qiu ◽  
Shu Ling Gao
Keyword(s):  
Fly Ash ◽  
Design Method ◽  
Orthogonal Experiment ◽  
Orthogonal Design ◽  
Steam Curing ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Early Strength ◽  
The Difference ◽  
Railway Sleeper

Using orthogonal design method of four factors and three levels, make a mix ratio experiment on sleeper concrete of China's railway sleepers, used steam curing concrete early compressive strength (stripping strength) as evaluation index. Study on different experimental factors of water-cement ratio, sand ratio, fly ash and admixture differently influenced on the early strength of sleeper concrete and analyze the difference impact of each factor and level for the orthogonal experiment. The result shows that the admixture is the main factor for early strength of concrete, followed by fly ash, water-cement ratio and sand ratio. It can provide technical guidance for railway sleeper field and has practical value.

Laboratory Experimental Research on Mix Ratio Test of Cement Soil

2013 ◽  
Vol 438-439 ◽  
pp. 197-201
Author(s):  
Xian Hua Yao ◽  
Peng Li ◽  
Jun Feng Guan
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Cement Content ◽  
Ratio Test ◽  
Curing Time ◽  
Curing Conditions ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Cement Soil

Based on the generalization and analysis of laboratory experimental results on mix ratio, the effects of various factors such as cement content, water-cement ratio, curing time, curing conditions and types of cement on the mechanical properties of unconfined compressive strength of cement soil are presented. Results show that the unconfined compressive strength of cement soil increases with the growing curing time, and it is greatly affected by the cement content, water-cement ratio, cement types and curing time, while the effect of curing conditions is weak with a cement content of more than 10%. Moreover, the stress-strain of the cement soil responds with the cement content and curing time, increasing curing time and cement content makes the cement soil to be harder and brittle, and leads to a larger Young's modulus.

scholarly journals An Experimental Study on Unconfined Compressive Strength of Soft Soil-Cement Mixtures with or without GGBFS in the Coastal Area of Vietnam

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Son Bui Truong ◽  
Nu Nguyen Thi ◽  
Duong Nguyen Thanh
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Unconfined Compressive Strength ◽  
Soft Soil ◽  
Soil Improvement ◽  
Treated Soil ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Granulated Blast Furnace Slag ◽  
Soil Cement

Soft soil is widely distributed in Vietnam, especially in the coastal area. In engineering practice, soft soil cannot be used to build any construction and needs to be improved or treated before building construction. In addition, Vietnam has many pig-iron or thermal power plants, which annually produce a huge amount of granulated blast furnace slag (GBFS). Thus, the use of this material for soft soil improvement needs to be considered. This paper presents experimental results on the unconfined compressive strength (UCS) of three Vietnam’s soft soils treated with Portland cement and Portland cement with ground granulated blast furnace slag (GGBFS). Binder dosage used in this study is 250, 300, and 350 kg/m3 with the three different water/cement ratios of 0.8, 0.9, and 1.0, respectively. The research results showed that the UCS of soil-cement mixtures depends on soil type, water/cement ratio, cement type, and binder content. Accordingly, the unconfined compressive strength increased with the increase of binder contents, the decrease of the natural water content of soft soil, water/cement ratios, and clay content. The highest value of UCS of treated soils was found for the soil at Site II with the Portland cement content, cement GGBFS, and water/cement ratio of 873 kg/m3, 2355 kg/m3, and 0.8, respectively. Besides, for all the three soils and two binder types, the water/cement ratio of 0.8 was found to be suitable to reach the highest UCS values of treated soil. The research results also showed that the UCS of treated soil with cement GGBFS was higher than that of treated soil with Portland cement. This indicated the effectiveness of the use of Portland cement with GGBFS in soft soil improvement. There is great potential for reducing the environmental problems regarding the waste materials from pig-iron plants in Vietnam and the construction cost as well.

Study on the Coexistence of Porous Ecological Concrete with Plants

2011 ◽  
Vol 311-313 ◽  
pp. 1551-1554 ◽  
Author(s):  
Hong Zhu Quan
Keyword(s):  
Cement Paste ◽  
Cement Content ◽  
Aggregate Gradation ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Concrete Blocks ◽  
Paste Content

The effects of mix proportions on the properties of porous ecological concrete, and its coexistence with plants are discussed in this paper. In conclusion, the strength of porous ecological concrete is governed simultaneously by water cement ratio and cement content. Permeability is increased with any increment in aggregate gradation and any decrease in cement paste content. The thicknesses of concrete blocks and topsoil affect the growth of plants.

scholarly journals Study on the Strength and Micro Characteristics of Grouted Specimens with Different Superfine Cement Contents

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6709
Author(s):  
Dongyue Zhang ◽  
Zhenqian Ma ◽  
Yihuai Zou ◽  
Hongfei Xie ◽  
Ruichong Guan
Keyword(s):  
Compressive Strength ◽  
Fractal Dimension ◽  
Cement Content ◽  
Uniaxial Compression Test ◽  
Injection Test ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Grouting Material ◽  
Comprehensive Performance ◽  
Scanning Electron

To provide the most effective comprehensive performance grouting material ratio, in this experimental investigation, a total of eight grouted specimens with two water-cement ratios (0.45:1, 0.55:1) and four different superfine cement contents (0%, 30%, 70%, 100%) were evaluated. Based on a uniaxial compression test, the fractal dimension of the fragments, a mercury injection test, and scanning electron microscopy, the effects of the superfine cement content on the strength characteristics and microscopic characteristics of the grouted specimens were studied. The results showed that increasing the superfine cement content could enhance the compressive and tensile strength of the grouted specimens and reduce the fractal dimension of the fragments and the porosity of the grouted specimens. The superfine cement content increased from 0% to 70% when the water-cement ratio was 0.45:1. The compressive strength of the grouted specimens increased from 16.7 MPa to 26.3 MPa, and the fractal dimension decreased from 1.8645 to 1.2301. When the water-cement ratio was 0.55:1, the compressive strength of the grouted specimens increased from 10.5 MPa to 20.6 MPa, and the fractal dimension value decreased from 2.2955 to 1.4458. When the superfine cement content increased from 0% to 100%, the water-cement ratio was 0.45:1. The porosity of the grouted specimens was reduced from 28.41% to 21.62%. When the water-cement ratio was 0.55:1, the porosity of the grouted specimens was reduced from 33.33% to 29.46%.

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