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Crushed rocks stabilized with organosilane and lignosulfonate in pavement unbound layers: Repeated load

Diego Maria BARBIERI, Inge HOFF, Chun-Hsing HO

《结构与土木工程前沿（英文）》 2021年第15卷第2期页码 412-424 doi: 10.1007/s11709-021-0700-5

摘要： The creation of the new “Ferry-Free Coastal Highway Route E39” in southwest Norway entails the production of a remarkable quantity of crushed rocks. These resources could be beneficially employed as aggregates in the unbound courses of the highway itself or other road pavements present nearby. Two innovative stabilizing agents, organosilane and lignosulfonate, can significantly enhance the key properties, namely, resilient modulus and resistance against permanent deformation, of the aggregates that are excessively weak in their natural state. The beneficial effect offered by the additives was thoroughly evaluated by performing repeated load triaxial tests. The study adopted the most common numerical models to describe these two key mechanical properties. The increase in the resilient modulus and reduction in the accumulated vertical permanent deformation show the beneficial impact of the additives. Furthermore, a finite element model was created to simulate the repeated load triaxial test by implementing nonlinear elastic and plastic constitutive relationships.

关键词： organosilane lignosulfonate crushed rocks pavement unbound layers repeated load triaxial test finite element analysis

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Organosilane surfactant-assisted synthesis of mesoporous SSZ-39 zeolite with enhanced catalytic performance

Hao Xu, Chi Lei, Qinming Wu, Qiuyan Zhu, Xiangju Meng, Daniel Dai, Stefan Maurer, Andrei-Nicolae Parvulescu, Ulrich Müller, Fengshou Xiao

《化学科学与工程前沿（英文）》 2020年第14卷第2期页码 267-274 doi: 10.1007/s11705-019-1845-9

摘要： SSZ-39 zeolite with AEI framework structure is a good catalyst candidate for the methanol-to-olefins (MTO) reaction. However, the diffusion limitation and coke formation often results in fast deactivation of the SSZ-39 zeolite catalyst. One solution for this challenge is to introduce mesoporosity in the SSZ-39 zeolite. Herein, we report the synthesis of mesoporous SSZ-39 zeolite using an organosilane surfactant, , -dimethyl- -(3-(trimethoxysilyl)propyl)octan-1-aminium chloride, as a mesopore template and , -dimethyl- -2,6-dimethylpiperidinium as a micropore template. The obtained zeolites were characterized by X-ray diffraction, N sorption, scanning electron microscopy, temperature programmed desorption of ammonia, and magic angle spinning nuclear magnetic resonance of Al. The results show that the mesoporous SSZ-39 zeolite has high crystallinity, meso/microporosity, high surface area, cuboid morphology, and abundant acidic sites. More importantly, this mesoporous SSZ-39 zeolite exhibits enhanced catalyst lifetime in the MTO reaction due to the presence of mesoporosity for fast mass transfer, compared with a conventional SSZ-39 zeolite without mesoporosity.

关键词： SSZ-39 zeolite mesopores organosilane surfactant MTO reaction soft template mass transfer