Binding Materials of Dehydrated Phases of Waste Hardened Cement Paste and Pozzolanic Admixture

Fly ash （FA） and ground granulated blast-furnace slag （GGBFS） were added to improve the performances of regenerated binding materials （RBM） which refer to dehydrated phases with rebinding ability of waste hardened cement paste. Flowability tests, compressive strength tests, SEM, TG-DSC, and non-evaporable water content tests were employed to study the performances of the combined binding materials and the interactions between RBM, FA, and GGBFS. Results show that adding FA or GGBFS can improve the workability of RBM paste, and GGBFS has positive effects on strength of RBM. Pozzolanic reactions happen between RBM, FA, and GGBFS. And the activation effect of RBM to FA and GGBFS is superior to that of P.O grade-32.5 cement, especially at earlier ages, because of the high reactive f-CaO existing in RBM. On the advantages of the synergetic effects of RBM and pozzolanic admixtures such as FA and GGBFS, new combined binding materials can be prepared by blending them together.

Plastic zone analysis and support optimization of shallow roadway with weakly cemented soft strata

Based on a shallow roadway with weakly cemented soft strata in western China, this paper studies the range and degree of plastic zones in soft strata roadways with weak cementation. Geological radars were used to monitor the loose range and level of surrounding rocks. A mechanical model of weakly cemented roadway was established, including granular material based on the measured results. The model was then used to determine the plastic zone radium. The predicted results agree well with measured results which provide valuable theoretical references for the analysis of surrounding rock stability and support reinforcing design of weakly cemented roadways. Finally, a combined supporting scheme of whole section bolting and grouting was proposed based on the original supporting scheme. It is proved that this support plan can effectively control the deformation and plastic zone expansion of the roadway surrounding rock and thus ensure the long-term stable and safe mining.

Vibrational power flow analysis on combined plates partially covered layer of discontinuous material

Vibrational power flow on combined plates with a change in mass and stiffness or with viscoelastic damping layer used widely in engineering is studied. The expressions of flexural displacement and other physical quantities are obtained using Laplace transformation and transfer matrix approach, then influences of changes in mass and stiffness of discontinuous material and the free damping layer on the input power flow and the transmitted power flow are discussed. The conclusions provide theory basis for structural optimization design and reducing noise and vibration

SINGLE AND DOUBLE EDGE INTERFACE CRACK SOLUTIONS FOR ARBITRARY FORMS OF MATERIAL COMBINATION

In this paper interfacial edge crack problems are considered by the application of the finite element method. The stress intensity factors are accurately determined from the ratio of crack-tip-stress value between the target given unknown and reference problems. The reference problem is chosen to produce the singular stress fields proportional to those of the given unknown problem. Here the original proportional method is improved through utilizing very refined meshes and post-processing technique of linear extrapolation. The results for a double-edge interface crack in a bonded strip are newly obtained and compared with those of a single-edge interface crack for different forms of combination of material. It is found that the stress intensity factors should be compared in the three different zones of relative crack lengths. Different from the case of a cracked homogeneous strip, the results for the double edge interface cracks are found to possibly be bigger than those for a single edge interface crack under the same relative crack length.

Development on astable multivibrators using the combination of linear and non-linear materials as switching elements based on all optial method

In this communication we propose a method to implement an all-optical astable multivibrator using the non-linear material based switches and logic gates. The scheme can operate in real time. The delay time can achieve ps(pico-second). The pulse duration can be made very low and may cross the THz easily by selecting proper material and laser source.

Exploiting the donor-acceptor-additive interaction’s morphological effect on the performance of organic solar cells

Organic solar cells(OSCs)have demonstrated over 19%power conversion efficiency(PCE)with the help of material innovation and device optimization.Co-working with newly designed materials,traditional solvent additives,1-chloronaphthalene(CN),and 1,8-diodooctane(DIO)are still powerful in morphology modulation towards satisfying efficiencies.Here,we chose recently reported high-performance polymer donors(PM6&D18-Fu)and small molecular acceptors(Y6&L8-BO)as active layer materials and processed them by different conditions(CN or DIO or none).Based on corresponding 12 groups of device results,and their film morphology characterizations(both ex-situ and in-situ ones),the property-performance relationships are revealed case by case.It is thereby supposed to be taken as a successful attempt to demonstrate the importance and complexity of donor-acceptoradditive interaction,since the device performance and physics analyses are also tightly combined with morphology variation.Furthermore,ternary blend construction for PCE improvement provides an approaching 19%level and showcases the potential of understanding-guided-optimization(UGO)in the future of OSCs.