scholarly journals The Performance of Carbonation-Cured Concrete

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3729
Author(s):  
Zhen Li ◽  
Zhen He ◽  
Xiaorun Chen
Keyword(s):  
Compressive Strength ◽  
Abrasion Resistance ◽  
Ph Value ◽  
Chloride Ion ◽  
Co2 Uptake ◽  
Ion Permeability ◽  
Micro Hardness ◽  
Steel Bar ◽  
Carbonation Curing ◽  
Better Than

The research shows that carbonation-cured concrete has several mechanical and durability properties that are better than those of moisture-cured concrete. However, many properties of carbonation-cured concrete have not yet been studied. In this research, carbonation-cured concrete was prepared by pre-curing, carbonation curing, and then moisture curing. The compressive strength, CO2 uptake, pH value, chloride ion permeability and abrasion resistance of the carbonation-cured concrete were investigated. Results showed that the compressive strength of carbonation-cured concrete was more than 10% higher than that of moisture-cured concrete at the same age; a steel bar is stable in carbonation-cured concrete; and carbonation-cured concrete exhibited better abrasion resistance and chloride ion permeability than that of moisture-cured concrete. The optimization of pore structure and improvement in the micro-hardness are the reasons for the improved chloride ion permeability and abrasion resistance of carbonation-cured concrete.

scholarly journals Mechanical Properties of High Strength Concrete Containing Nano SiO2 Made from Rice Husk Ash in Southern Vietnam

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 932
Author(s):  
Huu-Bang Tran ◽  
Van-Bach Le ◽  
Vu To-Anh Phan
Keyword(s):  
Compressive Strength ◽  
Rice Husk ◽  
High Strength Concrete ◽  
Rice Husk Ash ◽  
Chloride Ion ◽  
High Strength ◽  
Ion Permeability ◽  
Strength Concrete ◽  
Nano Sio2 ◽  
Southern Vietnam

This paper presents the experimental results of the production of Nano-SiO2 (NS) from rice husk ash (RHA) and the engineering properties of High Strength Concrete (HSC) containing various NS contents. Firstly, the mesoporous silica nanoparticles were effectively modulated from RHA using NaOH solution, and subsequently precipitated with HCl solution until the pH value reached 3. The optimum synthesis for the manufacture of SiO2 nanoparticles in the weight ratio of RHA/NaOH was 1:2.4, and the product was calcined at 550 °C for 2 h. The EDX, XRD, SEM, TEM, FT-IR, and BET techniques were used to characterize the NS products. Results revealed that the characteristics of the obtained NS were satisfactory for civil engineering materials. Secondly, the HSC was manufactured with the aforementioned NS contents. NS particles were added to HSC at various replacements of 0, 0.5, 1.0, 1.5, 2.0, and 2.5% by the mass of the binder. The water-to-binder ratio was remained at 0.3 for all mixes. The specimens were cured for 3, 7, 28, 25 days under 25 ± 2 °C and a relative humidity of 95% before testing compressive and flexural strengths. Chloride ion permeability was investigated at 28 and 56 days. Results indicated that the addition of NS dramatically enhanced compressive strength, flexural strength, chloride ion resistance, and reduced chloride ion permeability compared to control concrete. The optimal NS content was found at 1.5%, which yielded the highest strength and lowest chloride ion permeability. Next, the development of flexural and compressive strengths with an age curing of 3–28 days can be analytically described by a logarithmic equation with R2 ≥ 0.74. The ACI code was used, and the compressive strength at t-day was determined based on 28 days with R2 ≥ 0.95. The study is expected to solve the redundancy of waste RHA in southern Vietnam by making RHA a helpful additive when producing high-strength concrete and contributing meaningfully to a sustainable environment.

scholarly journals Effect of Lithium-Slag in the Performance of Slag Cement Mortar Based on Least-Squares Support Vector Machine Prediction

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1652 ◽  
Author(s):  
Jianghu Lu ◽  
Zhexuan Yu ◽  
Yuanzhe Zhu ◽  
Shaowen Huang ◽  
Qi Luo ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Compressive Strength ◽  
Least Squares ◽  
Cement Mortar ◽  
Chloride Ion ◽  
Industrial Wastes ◽  
Support Vector ◽  
Ion Permeability ◽  
Property Changes ◽  
Lithium Slag

There is a universally accepted view that environmental pollution should be controlled while improving cement mortar natural abilities. The purpose of this study is to develop a green cement mortar that has better compressive strength and anti-chloride ion permeability. Two industrial wastes, lithium-slag and slag, were added to cement mortar, and the role of lithium-slag was to activate slag. In addition, to save economic and time costs, this paper also used the least-squares support vector machine (LS-SVM) method to predict the property changes of cementitious-based materials. Then multiple natural abilities of samples, including compressive strength, anti-chloride ion permeability, and fluidity, were tested. In addition, LS-SVM and traditional support vector machine (SVM) were used to train and forecast the performance, including compressive strength. The results show that lithium-slag can activate slag to improve the compressive strength, anti-chloride ion permeability of mortar, and LS-SVM sharpens accuracy by 11% compared to SVM.

Effects of Compositions on the Chloride Ion Permeability of Geopolymer Concrete

2012 ◽  
Vol 450-451 ◽  
pp. 428-432
Author(s):  
Qing Wang ◽  
Jing Da ◽  
Cun Bao Zhang ◽  
Zhao Yang Ding ◽  
Zhi Tong Sui
Keyword(s):  
Chloride Ion ◽  
Cementitious Material ◽  
Molar Ratio ◽  
Geopolymer Concrete ◽  
Ion Permeability ◽  
Flux Method ◽  
Molar Ratios ◽  
Electric Flux ◽  
Better Than

The three key oxide molar ratios of geopolymer concrete were studied in this paper: n(SiO2)/n(Al2O3)，n(Na2O)/n(Al2O3) and n(H2O)/n(Na2O). The effect of each oxide molar ratio was assessed by electric flux method. It was found that resistance to chloride ion of geopolymer was increased with increasing n(SiO2)/n(Al2O3).However, there was a limit beyond which this performance improved; it performed better with the increasing of n(Na2O)/n(Al2O3) but worse with the increasing of n(H2O)/n(Na2O). With the same amount of cementitious material, resistance to chloride ion of geopolymer concrete was better than that of common concrete.

The Relationship between Concrete Road Performance and Salt Frost

2013 ◽  
Vol 857 ◽  
pp. 271-276
Author(s):  
Sheng Bo Zhou ◽  
Ai Qin Shen
Keyword(s):  
Abrasion Resistance ◽  
Chloride Ion ◽  
Ion Permeability ◽  
Mixture Ratio ◽  
Tensile Strength Test ◽  
Flexural Tensile Strength ◽  
Chloride Ion Penetration ◽  
Road Performance ◽  
Chlorine Ion ◽  
The Relationship

To carry out frost resistance, resistance to chlorine ion permeability, abrasion resistance and flexural tensile strength test for different mixture ratio of concrete, the influence of salt frost was systematically analyzed on the other concrete road performance. The results show that the salt frost made the decrease of strength of concrete, resistance to chloride ion penetration reduce, but had a little effects on abrasion resistance.

Influence Experimental Study on HPI Hydrophobic Compound Hole Plug Concrete Performance

2014 ◽  
Vol 584-586 ◽  
pp. 1527-1530
Author(s):  
Zhi De Huang
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Water Absorption ◽  
Chloride Ion ◽  
Ion Permeability ◽  
Concrete Compressive Strength ◽  
Hydrophobic Property ◽  
Hydrophobic Compound ◽  
Material Systems ◽  
Absorption Performance

Forming three groups concrete of different gelled material systems, the effecting of HPI hydrophobic compound hole plug on concrete compressive strength, chloride ion permeability resistance and water absorption performance were studied taking CALTITE and 3CC for example. Studies have shown that this kind of polymer can reduce compressive strength, but can improve chloride ion permeability resistance and hydrophobic property of concrete.

Properties of Self-Compacting Concrete Incorporating Rubber and Expanded Clay Aggregates

2014 ◽  
Vol 629-630 ◽  
pp. 417-424
Author(s):  
Ning Li ◽  
Guang Cheng Long ◽  
Si Si Zhang
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Coarse Aggregate ◽  
Chloride Ion ◽  
Dynamic Elastic Modulus ◽  
Fine Aggregate ◽  
Ion Permeability ◽  
Self Compacting Concrete ◽  
Clay Particles ◽  
Waste Rubber

Self-Compacting Concrete (SCC) incorporating a blend of normal aggregate and waste rubber or expanded clay aggregate were prepared in present paper. And then the properties of SCC incorporating combined aggregates in fresh state and hardened state, including workability, dynamic elastic modulus, compressive strength and chloride ion permeability were investigated by experiments. Results indicate that utilization of rubber particles as a fine aggregate or expanded clay particles as a coarse aggregate by partially replacing sand or coarse aggregate of the same volume can successfully produce the SCC with suitable workability. The addition of rubber or expanded clay particles results in a remarkable reduction of mechanical strength and dynamic elastic modulus of SCC. And the compressive strength and dynamic elastic modulus of SCC with expanded clay aggregate replacing coarse aggregate is higher than that of SCC with the same volume rubber replacing sand. The incorporation of rubber or expanded clay aggregate in concrete exhibits a reduction in chloride ion permeability as compared to normal concrete. It is of great importance for further understanding the effect of waste rubber and expanded clay aggregate on workability, mechanical properties and durability of SCC.

scholarly journals CO2 Uptake of Carbonation-Cured Cement Blended with Ground Volcanic Ash

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2187 ◽  
Author(s):  
Joon Seo ◽  
Issam Amr ◽  
Sol Park ◽  
Rami Bamagain ◽  
Bandar Fadhel ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Volcanic Ash ◽  
Blended Cement ◽  
Pozzolanic Reaction ◽  
Partial Replacement ◽  
Co2 Uptake ◽  
Supplementary Cementitious Material ◽  
Natural Minerals ◽  
The Matrix ◽  
Carbonation Curing

Accelerated carbonation curing (ACC) as well as partial replacement of cement with natural minerals are examples of many previous approaches, which aimed to produce cementitious products with better properties and environmental amicabilities. In this regard, the present study investigates CO2 uptake of carbonation-cured cement blended with ground Saudi Arabian volcanic ash (VA). Paste samples with cement replacement of 20%, 30%, 40%, and 50% by mass were prepared and carbonation-cured after initial curing of 24 h. A compressive strength test, X-ray diffractometry (XRD), and thermogravimetry were performed. Although pozzolanic reaction of VA hardly occurred, unlike other pozzolana in blended cement, the results revealed that incorporation of VA as a supplementary cementitious material significantly enhanced the compressive strength and diffusion of CO2 in the matrix. This increased the CO2 uptake capacity of cement, reducing the net CO2 emission upon carbonation curing.

scholarly journals CO2 Uptake and Physicochemical Properties of Carbonation-Cured Ternary Blend Portland Cement–Metakaolin–Limestone Pastes

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4656
Author(s):  
Rizwan Hameed ◽  
Joonho Seo ◽  
Solmoi Park ◽  
Issam T. Amr ◽  
H.K. Lee
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Ternary Blend ◽  
Co2 Uptake ◽  
Test Results ◽  
Ternary Blends ◽  
Replacement Level ◽  
Pore Characteristics ◽  
Compressive Strength Test ◽  
Carbonation Curing

The feasibility of carbonation curing of ternary blend Portland cement–metakaolin–limestone was investigated. Portland cement was substituted by the combination of metakaolin and limestone at levels of 15%, 30%, and 45% by the mass. The ternary blends were cured with four different combinations of ambient and carbonation curing. The mechanical property, CO2 uptake, and mineralogical variations of the ternary blend pastes were investigated by means of compressive strength test, thermogravimetric analysis, and X-ray diffractometry. In addition, volume of permeable voids and sorptivity of the ternary blends were also presented to provide a fundamental idea of the pore characteristics of the blends. The test results showed that the increasing amount of metakaolin and limestone enhanced the CO2 uptake, reaching 20.7% for the sample with a 45% cement replacement level at 27 d of carbonation. Meanwhile, the compressive strength of the samples was reduced up to 65% upon excessive incorporation of metakaolin and limestone. The samples with a replacement level of 15% exhibited a comparable strength and volume of permeable voids to those of the sample without substitution, proving that the ternary blend Portland cement–metakaolin–limestone can be a viable option toward the development of eco-friendly binders.

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