scholarly journals PORE STRUCTURE AND CHLORIDE ION BINDING CAPACITY OF CEMENT HARDENED BODY UNDER FROST DAMAGE

2012 ◽  
Vol 66 (1) ◽  
pp. 460-465
Author(s):  
Katsufumi HASHIMOTO ◽  
Hiroshi YOKOTA
2014 ◽  
Vol 599 ◽  
pp. 34-38 ◽  
Author(s):  
Ping Duan ◽  
Zhong He Shui ◽  
Guo Wei Chen

Layered double hydroxides (LDHs) materials could be used in cement and concrete for their ions capturing capacity and to enhance durability of concrete. In this work, properties and chloride binding capacity of different types of LDHs were compared, micro-mechanism of chloride binding of LDHs were analyzed and chloride binding of cement paste incorporating LDHs were investigated. The experimental results show that Mg-Al-NO3 LDHs presents higher chloride ion binding capacity at initial time compared to LDOs calcinated at 500 °C while ion binding capacity of LDHs calms down and LDOs increases with increasing mixing time. Cement paste incorporating LDHs presents higher chloride binding capacity compared with reference sample. All types of LDHs performed beneficial effect on the chloride penetration resistance especially with addition of 1% Mg-Al-NO3 LDOs.


2001 ◽  
Vol 31 (4) ◽  
pp. 577-588 ◽  
Author(s):  
Jolán Csizmadia ◽  
György Balázs ◽  
Ferenc D Tamás

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Katalin Kopecskó ◽  
György L. Balázs

Durability and service life of concrete structures can be endangered by chloride ions. Two phenomena help to keep control of chloride effects. On one hand cements are able to bind chloride ions by their aluminate clinker phases or by the clinker substituting materials. On the other hand resistivity of concrete against chloride penetration can be improved by careful selection of concrete constituents and production. Detailed results of two series of extensive experimental studies are presented herein. Chloride ion binding capacity of tested cements in decreasing sequence was the following: (1) CEM III/B 32,5 N-S; (2) CEM III/A 32,5 N; (3) CEM II/B 32,5 R; (4) CEM II/B-M (V-L) 32,5 R; (5) CEM I 42,5 N. Test results indicated that the increasing substitution of clinkers by GGBS improves the chloride resistivity in concrete made with the same water to cement ratio. The application of air entraining agent increases considerably the values of Dnssm. Based on the migration coefficients (Dnssm) the following sequence of efficiency was found (from the best): CEM III/B 32,5 N > CEM V/A (S-V) 32,5 N > CEM III/A 32,5 N > CEM II/B-S 42,5 R > CEM II/A-S 42,5 N > CEM I 42,5 N.


2013 ◽  
Vol 857 ◽  
pp. 105-109
Author(s):  
Xiu Hua Zheng ◽  
Shu Jie Song ◽  
Yong Quan Zhang

This paper presents an experimental study on the permeability and the pore structure of lightweight concrete with fly ash, zeolite powder, or silica fume, in comparison to that of normal weight aggregate concrete. The results showed that the mineral admixtures can improve the anti-permeability performance of lightweight aggregate concrete, and mixed with compound mineral admixtures further more. The resistance to chloride-ion permeability of light weight concrete was higher than that of At the same strength grade, the anti-permeability performance of lightweight aggregate concrete is better than that of normal weight aggregate concrete. The anti-permeability performance of LC40 was similar to that of C60. Mineral admixtures can obviously improve the pore structure of lightweight aggregate concrete, the total porosity reduced while the pore size decreased.


1965 ◽  
Vol 49 (4) ◽  
pp. 578-588 ◽  
Author(s):  
Fritz Reusser

ABSTRACT Bovine growth hormone was subjected to enzymatic hydrolysis by several crude proteolytically active streptomycete cell extracts. These digestion mixtures were fractionated on Sephadex gel columns. With each enzyme substantial amounts of hormonal aggregational products were formed during enzymatic hydrolysis with an apparent molecular weight exceeding the one for the native hormone. Fractions obtained retained various degrees of somatotrophic, lipolytic, and immunologic activities. In the course of these investigations it became apparent that the prepared bovine growth hormone fragments had a high inorganic ion binding capacity, in particular for Na+, Mg++, and SiO3−−.


2020 ◽  
Vol 10 (20) ◽  
pp. 7027-7033
Author(s):  
Surbhi Grewal ◽  
Saonli Roy ◽  
Himanshu Kumar ◽  
Mayank Saraswat ◽  
Naimat K. Bari ◽  
...  

A proof-of-concept on temporal control in the tritylation reactions has been demonstrated using a designed tripodal triazole-linked azo(hetero)arene-based photoswitchable catalyst.


2020 ◽  
Vol 10 (18) ◽  
pp. 6271 ◽  
Author(s):  
Jun Liu ◽  
Jiaying Liu ◽  
Zhenyu Huang ◽  
Jihua Zhu ◽  
Wei Liu ◽  
...  

This paper experimentally studies the effects of fly ash on the diffusion, bonding, and micro-properties of chloride penetration in concrete in a water soaking environment based on the natural diffusion law. Different fly ash replacement ratio of cement in normal concrete was investigated. The effect of fly ash on chloride transportation, diffusion, coefficient, free chloride content, and binding chloride content were quantified, and the concrete porosity and microstructure were also reported through mercury intrusion perimetry and scanning electron microscopy, respectively. It was concluded from the test results that fly ash particles and hydration products (filling and pozzolanic effects) led to the densification of microstructures in concrete. The addition of fly ash greatly reduced the deposition of chloride ions. The chloride ion diffusion coefficient considerably decreased with increasing fly ash replacement, and fly ash benefits the binding of chloride in concrete. Additionally, a new equation is proposed to predict chloride binding capacity based on the test results.


2018 ◽  
Vol 20 (5) ◽  
pp. 3381-3387 ◽  
Author(s):  
Kota Katayama ◽  
Yuji Furutani ◽  
Masayo Iwaki ◽  
Tetsuya Fukuda ◽  
Hiroo Imai ◽  
...  

ATR-FTIR spectroscopic study elucidates the novel role of Cl−-binding in primate long-wavelength-sensitive (LWS) visual pigment.


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