scholarly journals Cementitious Composites with High Compaction Potential: Modeling and Calibration

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4989
Author(s):  
Giao Vu ◽  
Tagir Iskhakov ◽  
Jithender Timothy ◽  
Christoph Schulte-Schrepping ◽  
Rolf Breitenbücher ◽  
...  
Keyword(s):  
Composite Materials ◽  
Lightweight Concrete ◽  
Calibration Procedure ◽  
Expanded Polystyrene ◽  
Potential Candidate ◽  
Novel Technologies ◽  
Annular Gap ◽  
Geological Conditions ◽  
Compressive Loads ◽  
Lightweight Composites

There is an increasing need for the development of novel technologies for tunnel construction in difficult geological conditions to protect segmental linings from unexpected large deformations. In the context of mechanized tunneling, one method to increase the damage tolerance of tunnel linings in such conditions is the integration of a compressible two-component grout for the annular gap between the segmental linings and the deformable ground. In this regard, expanded polystyrene (EPS) lightweight concrete/mortar has received increasing interest as a potential “candidate material” for the aforementioned application. In particular, the behavior of the EPS lightweight composites can be customized by modifying their pore structure to accommodate deformations due to specific geological conditions such as squeezing rocks. To this end, novel compressible cementitious EPS-based composite materials with high compaction potential have been developed. Specimens prepared from these composites have been subjected to compressive loads with and without lateral confinement. Based on these experimental data a computational model based on the Discrete Element Method (DEM) has been calibrated and validated. The proposed calibration procedure allows for modeling and prognosis of a wide variety of composite materials with a high compaction potential. The calibration procedure is characterized by the identification of physically quantifiable parameters and the use of phenomenological submodels. Model prognoses show excellent agreement with new experimental measurements that were not incorporated in the calibration procedure.

Cryogels as a solution to the issues of environmental management and trunk pipeline operation in Arctic

2020 ◽  
Vol 10 (2) ◽  
pp. 173-185
Author(s):  
Lyubov K. Altunina ◽  
◽  
Vladimir P. Burkov ◽  
Petr V. Burkov ◽  
Vitaly Y. Dudnikov ◽  
...  
Keyword(s):  
Composite Materials ◽  
Field Experiments ◽  
Oil And Gas ◽  
Soil Layer ◽  
Soil Microflora ◽  
Russian Arctic ◽  
Thaw Cycle ◽  
Trunk Pipeline ◽  
Geological Conditions ◽  
Spatial Lattice

In the Russian Arctic, a soil cryostructuring technique (i.e. strengthening of soil horizons with cryogel-based composite materials with no excavation of unstable soils required) seems to be showing promise. Experiments have proven that mechanical and thermal insulation properties attributed to cryogels make them appropriate for use in strengthening and thermally insulating the soil, while their structure makes it possible to form a stable vegetation cover. Field experiments have confirmed that cryostructuring efficiently strengthens the soil layer with cryogels stimulating soil microflora. An experience of using cryotropic compositions in the oil and gas sector was described. Notably, cryogels can be used to strengthen unstable soil foundations of trunk pipelines, as well as to bind soil (e.g. on slopes). In addition, cryogels are advised for use in engineering protection to prevent the uneven settlement of a trench base and its creep: thus, cryogels are pumped into the soil of the trench bottom base to create a support system representing a spatial lattice. After the first freeze and thaw cycle, cryotropic material is formed and then increases its strength and elasticity with each new cycle. More broadly, opportunities have been considered regarding cryogels used in various engineering and geological conditions, while taking into account the outcomes of landscape and territorial analysis. It was concluded that cryogel-based composite materials are a promising innovative scientific field expanding technological capabilities for developing and using spaces and resources in the Russian Arctic.

scholarly journals Structural Use of Expanded Polystyrene Concrete

2020 ◽  
Vol 5 (6) ◽  
pp. 1131-1138
Author(s):  
Adeniran Jolaade ADEALA ◽  
Olugbenga Babajide SOYEM
Keyword(s):  
Environmental Pollution ◽  
Lightweight Concrete ◽  
Physical And Mechanical Properties ◽  
Consumer Products ◽  
Expanded Polystyrene ◽  
Engineering Properties ◽  
Partial Replacement ◽  
Construction Companies ◽  
Fine Aggregates ◽  
Concrete Matrix

Expanded polystyrene (EPS) wastes are generated from industries and post-consumer products. They are non-biodegradable but are usually disposed by burning or landfilling leading to environmental pollution. The possibility of using EPS as partial replacement for fine aggregates in concrete has generated research interests in recent times. However, since the physical and mechanical properties of EPS are not like those of conventional fine aggregates, this study is focussed on the use of EPS as an additive in concrete while keeping other composition (sand and granite) constant. Expanded polystyrene was milled, the bulk density of EPS was 10.57kg/m3 and particle size distributions were determined. Engineering properties of expanded polystyrene concrete were determined in accordance with BS 8110-2:1985. The result showed that the amount of expanded polystyrene incorporated in concrete influence the properties of hardened and fresh concrete. The compressive strengths of 17.07MPa with 5 % expanded polystyrene concrete at 28 days for example can be used as a lightweight concrete for partitioning in offices. Incorporating expanded polystyrene granules in a concrete matrix can produce lightweight polystyrene aggregate concrete of various densities, compressive strengths, flexural strengths and tensile strengths. In conclusion, this reduces environmental pollution, reduction in valuable landfill space and also for sustainability in construction companies

Efficient Eco-friendly Composite Fluorine Anhydrite-Based Materials

2017 ◽  
Author(s):  
Grigory Yakovlev ◽  
Jadvyga Keriene ◽  
Anastasiia Gordina ◽  
Irina Polyanskikh ◽  
Milan Bekmansurov
Keyword(s):  
Water Absorption ◽  
Lightweight Concrete ◽  
Gas Permeability ◽  
Average Density ◽  
Expanded Polystyrene ◽  
Environmental Load ◽  
Great Demand ◽  
Technogenic Waste ◽  
And Performance ◽  
Reduced Water

The paper presents possible ways of utilizing technogenic waste – fluorine anhydrite – by its use in production of dry mortars and piece goods from lightweight concrete with expanded polystyrene, as a organic filler, for low-rise construc-tion. The developed dry mortars are based on fluorine anhydrite binder and complex modifier comprising curing activator (sulfate or alkaline) and finely dispersed additive. The fluorine anhydrite-based compositions have improved physical and performance characteristics, including the improved strength and average density and reduced water absorption compared to the control composition. The developed lightweight anhydrite polystyrene concrete has the density grade of 700 kg/m3 and good vapor and gas permeability. The concrete is stabile while using and fire safe, because each granule of expanded poly-styrene is coated with anhydrite matrix, and has the strength sufficient for structural and heat insulating slabs and blocks. All mentioned compositions are eco-friendly and are in great demand for low-rise construction. Therefore the manufacturing of these compositions will consume a large amount of technogenic waste and will reduce the environmental load on the region where the waste is located.

Prediction of compressive strength and elastic modulus of expanded polystyrene lightweight concrete

2015 ◽  
Vol 67 (17) ◽  
pp. 954-962 ◽  
Author(s):  
Yi Xu ◽  
Linhua Jiang ◽  
Jinxia Xu ◽  
Hongqiang Chu ◽  
Yang Li
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Lightweight Concrete ◽  
Expanded Polystyrene

scholarly journals RECOVERY OF WASTE EXPANDED POLYSTYRENE IN LIGHTWEIGHT CONCRETE PRODUCTION

2019 ◽  
Vol 34 (3) ◽  
pp. 73-80
Author(s):  
Gordan Bedeković ◽  
◽  
Ivana Grčić ◽  
Aleksandra Anić Vučinić ◽  
Vitomir Premur ◽  
...  
Keyword(s):  
Lightweight Concrete ◽  
Expanded Polystyrene ◽  
Concrete Production

Lightweight Concrete Precast Panels for the Improvement of Thermal Insulation of Housing with Expanded Polystyrene Beads

2021 ◽  
Vol 1033 ◽  
pp. 163-171
Author(s):  
Alexandra Reto ◽  
Renzo Sanabria ◽  
José Rodriguez ◽  
Alexandra Hinostroza
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Insulation ◽  
Lightweight Concrete ◽  
Linear Trend ◽  
Precast Concrete ◽  
Expanded Polystyrene ◽  
Dry Density ◽  
Conventional Concrete ◽  
Polystyrene Beads

The precast concrete elements in the construction of buildings are increasingly used due to their better quality control, constructive speed, reduction of the number of workers and less waste of resources compared to conventional construction; for wall applications, to these advantages, the design to ensure thermal comfort requires the improvement of the low thermal insulation of conventional concrete panels. The use of materials with lower thermal conductivity such as Expanded PolyStyrene Beads (EPSB) in lightweight concrete for the construction of precast panels in housing, contributes to improve thermal insulation and the saving operational energy during its operation phase, because the aggregate has a small size, low density and thermal conductivity; applied in higher volumes in concrete, reduces indoor heat loss in cold climates and indoor heat gain in warm climates in housing. The purpose of this research is to study the behavior of lightweight concrete with EPSB for 16%, 26% and 36% addition and evaluate the air-dry density, compressive strength, thermal conductivity, relationship between air-dry density with compressive strength and thermal conductivity. The results indicate that the higher the percentage of EPSB the air-dry density, compressive strength and thermal conductivity decrease; the relationships between air-dry density with compressive strength and thermal conductivity follow a linear trend and are similar.

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