scholarly journals Effect of Curing on Mechanical Properties of Cement-Stabilized Coral Sand in Marine Environment

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Mingyuan Chen ◽  
Jiuguang Geng ◽  
Haocheng Xiong ◽  
Tao Shang ◽  
Cheng Xue ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fresh Water ◽  
Marine Environment ◽  
Cement Content ◽  
Early Stage ◽  
Road Construction ◽  
Chloride Ion ◽  
Ion Concentration ◽  
Water Mixing ◽  
Coral Sand

The use of coral sand prepared from cement-stabilized materials can significantly reduce the cost, construction period, and damage to the environment caused by stone mining. The choice of water in mixing and curing the cement-stabilized materials on islands should be considered. Cement-stabilized coral sand was tested in three different preparation and maintenance systems in the marine environment. The compressive strength, weight change, and chloride ion concentration change in cement-stabilized coral sand with different cement content were measured after 7 d, 28 d, 60 d, and 90 d, respectively. The microstructure of specimens was observed by XRD and SEM. Results show that the compressive strength of specimens in the seawater mixing and seawater curing system developed 0.9 MPa faster than that in the fresh water mixing and curing system at an early stage. But the compressive strength of specimens in seawater mixing and seawater curing shrank later, being 0.5 MPa lower than that in fresh water mixing and curing. The cement content was positively correlated with the free chloride ion reaction and mass growth rate. For road construction on islands, the mixing and curing of cement-stabilized coral sand with seawater should be given priority in the early stage.

scholarly journals ANALYSIS INFLUENCE OF CEMENT OF THE ASPHALT PAVEMENT DEMOLITION MATERIAL ON ROADS SEMARANG-DEMAK-INDONESIA

2017 ◽  
pp. 73-78
Author(s):  
P. Pratikso ◽  
A. Purwanto ◽  
S. Sudarno
Keyword(s):  
Compressive Strength ◽  
Technology Development ◽  
Cement Content ◽  
Asphalt Pavement ◽  
Construction Material ◽  
Road Construction ◽  
Dry Weight ◽  
Natural Material ◽  
Road Infrastructure ◽  
Asphalt Cement

Natural resources such as natural material such as stone, sand, asphalt which has long been used by humans for road construction because of the limited experience any material taken will collide with the preservation of the environment so that the construction work of road infrastructure obstacles and ultimately can lead to the work stalled road infrastructure. To overcome these problems it is necessary to the implementation of the technology development of road infrastructure by using recycled (recycling). The purpose of this study is to determine levels of cement that can be used for the top layer foundation (base course) with recycled materials mixed asphalt cement / Cement Treated Recycling Base (CTRB) on road rehabilitation Semarang - Demak and to determine the uncondifined compressive strength that occurs so that the material can be reused as construction material pavement layer. This study uses an experimental method in the laboratory with a cylindrical specimen diameter of 7 cm height of 14 cm made of asphalt pavement scratching Semarang-Demak roads with cement content variation 0%, 1.5%, 3%, 4.5%, 6% and 7.5% is used for testing the uncondifined compressive strength / (UCS) at the age of 7 days, 21 days, 14 days and 28 days. The results show that the addition of cement content will increase the value of the dry weight insignificantly, but will rise UCS value significantly and utilization of scratching asphalt cement with added material from these laboratory experiments can increase the carrying capacity CTRB construction. Levels of cement that meets the requirements of Unconfined Compressive Strength (UCS) for the construction of Cement Treated Recycling Base (CTRB) is between 6% to 7.5%. According to the results of research it is economically to used cement content at average of 6.75% for road rehabilitation works Semarang - Demak has met the required UCS test.

scholarly journals Effect of Modifying Aggregates by Rap and the Simultaneous use of Adhesives for the Stabilization of a Sandy Pavement Subgrade

2021 ◽  
Vol 29 (2) ◽  
pp. 1-8
Author(s):  
Mohammad Mehdi Khabiri ◽  
Bahareh Ebrahimialavijeh
Keyword(s):  
Compressive Strength ◽  
Construction Projects ◽  
Cement Content ◽  
Road Construction ◽  
Environmental Issues ◽  
Dune Sand ◽  
Strength Parameters ◽  
Recycled Asphalt ◽  
Surface Method ◽  
Strength Tests

Abstract The improvement, reconstruction and repair of roads in recent years have increased the content of recycled asphalt in pavements. Using these materials in road construction projects because they reduce the costs, will also be of great help in improving environmental issues. In the present study, dune sand, which can be found in most desert area soil but does not have proper strength and loading capacity for a subgrade, was used. In order to increase the strength parameters of dune sand, various contents of cement and recycled asphalt were examined in California Bearing Ratio (CBR) and compressive strength tests. The results showed that the addition of cement and recycled asphalt can increase compressive strength and bearing capacity and reduce rupture deformations. In a stabilized sample with 27.5% recycled asphalt, increasing the cement from 7.5 to 12.5% increased the compressive strength by 1.045 times, which is the highest amount of change in the samples studied. The maximum CBR and minimum rupture deformations are related to 35% of the recycled asphalt and 12.5% of the cement. The predicted functions of the compressive strength, deformation and CBR depend on two variables of the cement content; the recycled asphalt was then calculated using the response surface method

Experimental Study on Influence of Bending Load on Chloride Ion Concentration of Concrete in Marine Environment

2014 ◽  
Vol 919-921 ◽  
pp. 460-464
Author(s):  
Han Yang Jin ◽  
Hua Xia Zhuang ◽  
Ru Tai Liu ◽  
Jia Le Shi ◽  
Jun Zhi Zhang
Keyword(s):  
Marine Environment ◽  
Concrete Beams ◽  
Chloride Ion ◽  
Load Level ◽  
Ion Concentration ◽  
Tension Zone ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Free Chloride ◽  
Bending Load

This paper mainly determined free chloride ion concentration of concrete beams of two kinds of water cement ratio (0.45and0.60) and bending load (0.00Fmax, 0.30Fmax, 0.45Fmax and 0.60Fmax) after 240 d in marine environment and compared the effect of different load conditions in the same water cement ratio on the free chloride ion concentration. The results show that the concentration of free chloride ion in tension zone of concrete increases with the increase of load level, the concentration of free chloride ion in compressed zone of concrete decreases with the increase of load level; under the same bending load level, the concentration of free chloride ion in concrete increases with water cement ratio.

scholarly journals Experimental Study on the Influence of Rubber Content on Chloride Salt Corrosion Resistance Performance of Concrete

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4706
Author(s):  
Danyang Su ◽  
Jianyong Pang ◽  
Xiaowen Huang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Corrosion Resistance ◽  
Chloride Ion ◽  
Ion Concentration ◽  
Chloride Salt ◽  
Rubber Content ◽  
Ordinary Concrete ◽  
Salt Corrosion ◽  
Rubber Concrete

In order to enhance the corrosion resistance of concrete to chloride salt, 5% NaCl solution was used to corrode ordinary concrete (OC) and rubber concrete (RC) with 5%, 10%, and 15% rubber content, respectively. By testing the compressive strength, mass, chloride ion concentration at different depths and relative dynamic elastic modulus, the erosion mechanism was analyzed by means of SEM scanning and EDS patterns, and the mechanical properties and deterioration degree of ordinary concrete (OC) and rubber concrete (RC) under the corrosion environment of chloride salt were studied. The results show that: the quality of rubber mixed into concrete increases first and then decreases, and rubber can increase the compressive strength of concrete, improve its internal structure. At the same time, the mechanical properties of concrete in the corrosion environment of chloride salt are improved to a certain extent, and the deterioration degree is reduced. Considering the comprehensive performance of OC and RC in the dry–wet alternation mechanism under chloride salt corrosion, the best content of rubber is 10%.

scholarly journals The Impact of Chloride and Sulphate Aggressiveness on the Microstructure and Phase Composition of Fly Ash-Slag Mortar

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4430
Author(s):  
Paweł Falaciński ◽  
Agnieszka Machowska ◽  
Łukasz Szarek
Keyword(s):  
Compressive Strength ◽  
Phase Composition ◽  
Sodium Chloride ◽  
Chloride Ion ◽  
Sodium Sulphate ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Pore Liquid ◽  
A Minor ◽  
The Impact

The article discusses the results of examining the impact of aggressive solutions on specimens of mortars with a slag-ash binder. Bar specimens were exposed to unidirectional diffusion of sodium chloride and sodium sulphate for 90 days. Next, the specimens were subjected to flexural and compressive strength tests, ion content tests, XRD phase composition tests, and microstructural SEM-EDS tests. The test results indicated that aggressive solution action resulted in decreased flexural strength, however, it did not impact the compressive strength of mortars. A minor impact of chloride ions on the pH of the pore liquid was recorded, while the tests did not show any influence of sulphate ions. Furthermore, aggressive ion concentration decreased in deeper specimen slices. Specimen phase composition testing after chloride ion action indicated the presence of a small amount of Friedel’s salt, while regular sodium chloride crystals were identified in the microscopic image. The performance properties of mortars exposed to the action of aggressive solutions were maintained.

Study on Service Life of OPC and HPC in Marine Environment

2019 ◽  
Vol 805 ◽  
pp. 161-169
Author(s):  
Hao Yu Chen
Keyword(s):  
Service Life ◽  
Marine Environment ◽  
High Performance ◽  
High Performance Concrete ◽  
Chloride Ion ◽  
Ion Concentration ◽  
Portland Cement Concrete ◽  
Tidal Zone ◽  
Environment Exposure ◽  
Degradation Effect

In this paper, ordinary Portland cement concrete (OPC) and high performance concrete (HPC) were used in the marine environment exposure experiments, Using the second Fick’s law, five parameter of life prediction model-binding ability, diffusion coefficient of free C1- time dependent parameters, chloride ion concentration of surface and degradation effect coefficients are confirmed. The service life of OPC and HPC in ocean conditions is calculated and compared using mathematic software in atmosphere region, underwater region and tidal zone.

scholarly journals Experimental Investigation on Deterioration Mechanisms of Concrete under Tensile Stress-Chloride Ion-Carbon Dioxide Multiple Corrosion Environment

2022 ◽  
Vol 10 (1) ◽  
pp. 80
Author(s):  
Xiangsheng Chen ◽  
Jun Shen
Keyword(s):  
Carbon Dioxide ◽  
Compressive Strength ◽  
Tensile Stress ◽  
Marine Environment ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Water Soluble ◽  
Limited Information ◽  
Carbonation Depth ◽  
The Impact

The adverse effects of a hostile marine environment on concrete structures inevitably result in great economic loss and may contribute to catastrophic failure. There is limited information on the durability of concrete in a tensile stress-chloride ion-carbon dioxide (TCC) multiple-corrosion environment. The objective of this study is to explore the impact of a TCC multiple-corrosion environment on concrete considering three coupled factors of compressive strength, Cl− penetration, and carbonation. Dry–wet cycle tests were conducted to determine the strength degradation and Cl− penetration concentration of concrete in a hostile multiple-corrosion marine environment. The results show that the effects of water-soluble chloride ions (Cl−), carbon dioxide (CO2), and tensile stress on concrete are not a simple superposition, but involve obvious interaction. The compressive strength of a concrete specimen first increases and then decreases in chlorine salt-carbon tests. The Cl− concentration and tensile stress affect the carbonation depth of concrete, which increases with an increase in Cl− concentration, and with the application of tensile stress. The Cl− concentration has an obvious effect on the carbonation depth. In addition to experimental observations, a stepwise regression equation was established based on the multiple linear regression theory. A correlation analysis considering different factors was conducted to reflect the corrosion results more directly.

Research on Compressive Properties of Sea Sand Concrete

2014 ◽  
Vol 881-883 ◽  
pp. 1221-1224 ◽  
Author(s):  
Wei Zhang
Keyword(s):  
Compressive Strength ◽  
Compression Test ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Compressive Properties ◽  
River Sand ◽  
Strength Performance ◽  
Sea Sand

The chloride ion concentration of sea sand were measured by Volhard method and identified the method of removal chloride ions in sea sand. By comparison of compression test for sea sand concrete and river sand concrete ,two compressive strength performance is basically the same , Verify the feasibility of the concrete of the treated sea sand for bluiding.

scholarly journals First Attempts of the Use of 195Pt NMR of Phenylbenzothiazole Complexes as Spectroscopic Technique for the Cancer Diagnosis

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3970 ◽  
Author(s):  
Bruna T. L. Pereira ◽  
Mateus A. Gonçalves ◽  
Daiana T. Mancini ◽  
Kamil Kuca ◽  
Teodorico C. Ramalho
Keyword(s):  
Cancer Treatment ◽  
Cancer Diagnosis ◽  
Density Functional ◽  
Chemical Shifts ◽  
Chloride Ion ◽  
Platinum Complexes ◽  
Dft Method ◽  
Ion Concentration ◽  
Implicit Solvent ◽  
Early Cancer Diagnosis

Platinum complexes have been studied for cancer treatment for several decades. Furthermore, another important platinum characteristic is related to its chemical shifts, in which some studies have shown that the 195Pt chemical shifts are very sensitive to the environment, coordination sphere, and oxidation state. Based on this relevant feature, Pt complexes can be proposed as potential probes for NMR spectroscopy, as the chemical shifts values will be different in different tissues (healthy and damaged) Therefore, in this paper, the main goal was to investigate the behavior of Pt chemical shifts in the different environments. Calculations were carried out in vacuum, implicit solvent, and inside the active site of P13K enzyme, which is related with breast cancer, using the density functional theory (DFT) method. Moreover, the investigation of platinum complexes with a selective moiety can contribute to early cancer diagnosis. Accordingly, the Pt complexes selected for this study presented a selective moiety, the 2-(4′aminophenyl)benzothiazole derivative. More specifically, two Pt complexes were used herein: One containing chlorine ligands and one containing water in place of chlorine. Some studies have shown that platinum complexes coordinated to chlorine atoms may suffer hydrolyses inside the cell due to the low chloride ion concentration. Thus, the same calculations were performed for both complexes. The results showed that both complexes presented different chemical shift values in the different proposed environments. Therefore, this paper shows that platinum complexes can be a potential probe in biological systems, and they should be studied not only for cancer treatment, but also for diagnosis.

Diffusion of chloride ion in coral aggregate seawater concrete under marine environment

2021 ◽  
Vol 284 ◽  
pp. 122821
Author(s):  
Gang Wang ◽  
Qing Wu ◽  
Hao Zhou ◽  
Chen Peng ◽  
Wei Chen
Keyword(s):  
Marine Environment ◽  
Chloride Ion
Sign in / Sign up

Export Citation Format

Share Document