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Home > Publications > International Concrete Abstracts Portal
The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.
Showing 1-5 of 37 Abstracts search results
Document:
SP329
Date:
October 2, 2018
Author(s):
Jiaping Liu, Ziming Wang, Terence C. Holland, Jing Huang, Johann Plank
Publication:
Symposium Papers
Volume:
329
Abstract:
On October 28-31, 2018, the Chinese Ceramic Society and the China Academy of Building Research (CABR), Beijing China, in association with ACI, sponsored the Twelfth International Conference on Superplasticizers and other Chemical Admixtures in Concrete in Beijing China. More than 80 papers from all over the world were received and peer reviewed. A total of 36 refereed papers were accepted for publication in the proceedings of the conference. The proceedings were published by the ACI as SP 329. Also, 54 additional papers were presented at the conference, and were published in the Supplementary Papers Volume. The organizers of the conference were the Chinese Ceramic Society, Beijing and the Committee for the Organization of International Conferences (formerly CANMET/ACI Conferences).
DOI:
10.14359/51712247
SP-329-09
September 26, 2018
ShanShan Qian, SuPing Cui, ChunYang Zheng, ZiMing Wang, and Yan Yao
In this study, phosphate-based polycarboxylate superplasticizer (PPS) was successfully prepared via precise design and control over the molecular structure. Macromolecules with pendant chlorine groups are synthesized via free radical polymerization (FRP) and atom transfer radical polymerization (ATRP) of 2-hydroxyethyl acrylate, vinylbenzyl chloride and isoamyl alcohol polyoxyethylene ether in the presence of initiator, chain transfer agent and metal complex. The subsequent Arbuzov reaction (AR) between trimethoxyphosphine and chlorine groups of macromolecules gave rise to new type of PPS. The molecular structure of PPS is determined by Fourier Transform Infrared Spectroscopy, 1H Nuclear Magnetic Resonance and Gel Permeation Chromatography, respectively. The surface tension, Zeta potential, adsorption behavior and application performance in concrete are measured. The result shows that PPS we prepared has excellent clay-inerting and high slump retention capability.
10.14359/51711207
SP-329-10
Ying Qiu, Guo-Xin Chen, Ye-Ran Zhu, Xiu-Sheng Tang, and Zheng Cui
A high-performance liquid alkali-free setting accelerator (HSL) in sprayed concrete was prepared by dimethyl sulfoxide modified sepiolite and aluminum hydroxide as the main raw materials. The sprayed concrete rebound have been investigated by concrete penetration resistance tester. Its set accelerating mechanism is studied by pore structure analysis,XRD characterization methods. The pore structure analysis shows that the total porosity and pores larger than 3.94 in. [100 mm] of cement pastes mixed with HSL are slightly reduced after 28 days hydration and the hydration of C3A was accelerated by the polyamine complexation of accelerator, resulting in forming a large number of acicular ettringite and reducing the amount of Ca(OH)2 crystal, which will not affect the later hydration of cement,to improve the final compressive strength. The 1day compressive strength of the concrete mixed with HSL reaches 22.3 MPa (3234 psi), the 28 days compressive strength ratio increasing by 118.5%.
10.14359/51711208
SP-329-11
Giorgio Ferrari, Mariele Gamba, Francesco Surico, Gilberto Artioli, Maria Chiara Dalconi, and Luca Valentini
Expandable clays are highly detrimental to PCEs because of the possibility to intercalate PCEs molecules into the clay interlayer. In this work, the interaction of PCEs with such type of clay was studied by XRPD and adsorption measurements and the effect of clay on the fluidity of cement pastes was measured by mini-slump test. Smectite clay has been mixed in synthetic cement pore solution with different PCEs based on methacrylic acid/MPEG methacrylate copolymers. Results confirmed that the presence of expandable clays reduces the cement paste fluidity because of the possibility to intercalate PCE molecules and the formation of hydrogel between PCE and clay. It was found that the sensitivity to expandable clay depends on the PCE molecular weight and the shift in the position of the 001 diffraction peak of the clay, which is a direct measurement of the tendency of different PCEs molecules to intercalate into swelling clays.
10.14359/51711209
SP-329-06
Vipasri Kanchanason and Johann Plank
The influence of an isoprenyl oxy poly(ethylene glycol) (IPEG) based PCE on the nucleation and crystallization of C-S-H precipitated from aqueous solutions of Ca(NO3)2 and Na2SiO3 was investigated. It was found that in the absence of IPEG-PCE, globular nanoparticles of C-S-H with a diameter of ~50 nm [1.97 x 10-6 in.] are formed. Subsequently, within an hour the globules convert to C-S-H nanofoils with ~150 nm [5.91 x 10-6 in.] length following a non-classical nucleation mechanism. In the presence of the PCE, the initial globules show a core-shell structure whereby a layer; presumably PCE polymer, coats the C-S-H core. The shell around the C-S-H globules delays the conversion to the nanofoils for several hours and leads to significantly smaller foils and a superior seeding material in cement.
10.14359/51711204
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