Structures and hydration activities of alumi-nates CA and CA2 of cement minerals are studied by SCF —DV —Xa method, one of the molecular orbital calculating method in quantum chemistry. The calculated results of net...Structures and hydration activities of alumi-nates CA and CA2 of cement minerals are studied by SCF —DV —Xa method, one of the molecular orbital calculating method in quantum chemistry. The calculated results of net charges,energy levels of molecular orbitals and covalent bond orders are all consistent with the experimental result that the hydration activity of CA is higher than that of CA2.展开更多
Fugitive dust was cemented, forming larger particles bond in the calcite-consolidation-layer by microbial method. The particular composition, the morphology, and thermal decomposition properties of the samples were ch...Fugitive dust was cemented, forming larger particles bond in the calcite-consolidation-layer by microbial method. The particular composition, the morphology, and thermal decomposition properties of the samples were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, Fourier transform infrared（FTIR） spectroscopy, and differential scanning calorimetry-thermogravimetry（DSC-TG）. The characterization data obtained showed that loose fugitive dust particles could be bonded and formed the consolidation-layer under the effect of calcite obtained by microbial method successfully. Meanwhile, the sample obtained by microbial method had superior wind-erosion resistance.展开更多
F mineral admixture (FMA) is made of the fin- ely divided powder of natural zeolite with a bit of other agent. When FMA is used to displace about 10% (by weight) of the ordinary portland cement (OPC) (strength grade 5...F mineral admixture (FMA) is made of the fin- ely divided powder of natural zeolite with a bit of other agent. When FMA is used to displace about 10% (by weight) of the ordinary portland cement (OPC) (strength grade 575#) in concrete and mixed with a suitable amount of super plasticizer (w/c =0.31-0.35), then a high-strength concrete with compressive strength about 80 MPa and slump about 180 MM can be obtained. The strength of this concrete is about 10-15% higher than that of the corresponding concrete mixing with pure OPC, and its bleeding decreases greatly. It makes no segre- gation and separation, and thus it satisfies the requirement of pumping concrete in construction.展开更多
Structures and hydration activities of ferro-aluminates (Ca2Fe2-xAlxO5 ,x = 0.0. 57 and 0. 72) of cement minerals are studied by SCF-DV-Xa method. one of the molecular orbital calculating method in quantum chemistry. ...Structures and hydration activities of ferro-aluminates (Ca2Fe2-xAlxO5 ,x = 0.0. 57 and 0. 72) of cement minerals are studied by SCF-DV-Xa method. one of the molecular orbital calculating method in quantum chemistry. The calculated results of net charges, energy levels of molecular orbitals and covalent bond orders are all consistent with the increase of Al element, there is superior hydration activity of Ca2Fe2-xAlxO5.展开更多
文摘Structures and hydration activities of alumi-nates CA and CA2 of cement minerals are studied by SCF —DV —Xa method, one of the molecular orbital calculating method in quantum chemistry. The calculated results of net charges,energy levels of molecular orbitals and covalent bond orders are all consistent with the experimental result that the hydration activity of CA is higher than that of CA2.
基金Funded by the National Natural Science Foundation of China(No.51372038)the Scientific Research Foundation of Graduate School of Southeast University(YBJJ1566)
文摘Fugitive dust was cemented, forming larger particles bond in the calcite-consolidation-layer by microbial method. The particular composition, the morphology, and thermal decomposition properties of the samples were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, Fourier transform infrared（FTIR） spectroscopy, and differential scanning calorimetry-thermogravimetry（DSC-TG）. The characterization data obtained showed that loose fugitive dust particles could be bonded and formed the consolidation-layer under the effect of calcite obtained by microbial method successfully. Meanwhile, the sample obtained by microbial method had superior wind-erosion resistance.
文摘F mineral admixture (FMA) is made of the fin- ely divided powder of natural zeolite with a bit of other agent. When FMA is used to displace about 10% (by weight) of the ordinary portland cement (OPC) (strength grade 575#) in concrete and mixed with a suitable amount of super plasticizer (w/c =0.31-0.35), then a high-strength concrete with compressive strength about 80 MPa and slump about 180 MM can be obtained. The strength of this concrete is about 10-15% higher than that of the corresponding concrete mixing with pure OPC, and its bleeding decreases greatly. It makes no segre- gation and separation, and thus it satisfies the requirement of pumping concrete in construction.
文摘Structures and hydration activities of ferro-aluminates (Ca2Fe2-xAlxO5 ,x = 0.0. 57 and 0. 72) of cement minerals are studied by SCF-DV-Xa method. one of the molecular orbital calculating method in quantum chemistry. The calculated results of net charges, energy levels of molecular orbitals and covalent bond orders are all consistent with the increase of Al element, there is superior hydration activity of Ca2Fe2-xAlxO5.
