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To the old cement concrete pavement which lost the overall loading capacity and large areas are damaged, by using rubblization technology to shocks, crushing and compaction it, pouring the warm-mix asphalt sealing, formed less than 60mm size of flexible base of gravel and paved with warm-mix asphalt pavement on this base. This article is about analysis of interlinear stresses of pavement structure and production cost analysis of mixture on this combination structure. Proved that the structure could in-place recycling, solving the environmental issues of dropped cement pieces garbage. Mix in mixture, spreading process of reducing harmful gas emissions, can save more than 30% of construction costs.

Fine powders of Ln 0.6 Ca 0.4 FeO 3−δ (Ln Pr, Nd, Sm) were prepared by a glycine-nitrate process (GNP). The preparation process, thermal properties, phase constituents, and microstructure of the samples were characterized by FT-IR, TG-DSC, XRD and TEM, respectively. The results show that all of the powders have perovskite-type structure with orthorhombic symmetry and mean particle size of 25 nm. The relative density of Pr 0.6 Ca 0.4 FeO 3−δ and Nd 0.6 Ca 0.4 FeO 3−δ decreased with sintering temperature, while increased for Sm 0.6 Ca 0.4 FeO 3−δ . The DC four-probe measurement indicated that both Pr 0.6 Ca 0.4 FeO 3−δ and Nd 0.6 Ca 0.4 FeO 3−δ exhibit fairly high electrical conductivity, over 100 S cm −1 at T > 650 °C, high enough for application as cathode materials for IT-SOFC. The temperature dependence of the conductivity for Nd 0.6 Ca 0.4 FeO 3−δ consists of two straight lines with activation energies of 160.2 and 18.6 kJ mol −1 , respectively, for the sample sintered at 1100 °C for 2 h. The conduction mechanism of the materials is discussed in terms of non-stoichiometry.

Perovskite Sm1-xSrxCoO3 ceramics have been successfully prepared by gelcasting from oxides and carbonate powders, which were characterized by sintering the gels cast from a suspension of low-solubility metallic oxide precursors and organic monomers. The porosity, pore size, microstructure and electrical conductivity of the obtained Sm1-xSrxCoO3 ceramics were also investigated. It has been shown that single Sm1-xSrxCoO3 perovskite phase forms at a relatively low calcination temperature of 1000°C. Especially, porous Sm1-xSrxCoO3 ceramics with homogeneous microstructure can be obtained by controlling sintering process of the gelcasts. In addition, the Sm1-xSrxCoO3 ceramics show good electrical conductivity, which can meet the demand for solid oxide fuel cell cathode application.

La1-xCaxCrO3 (0.1≤ x ≤ 0.4) is usually used as interconnect material for solid oxide fuel cells (SOFCs). In this paper, composite material, the two-phase mixtures of face-centered cubic fluorite structure CayCe1-yO2-y (0 ≤ y≤ 0.2) and orthorhombic perovskite structure [Sm(Eu,Gd)]1-zCazCrO3 (0 < z < 0.3), was prepared by an auto-ignition process in which mixed rare earth oxides (Sm2O3, Gd2O3, Eu2O3 and CeO2) are substituted for La2O3 in La1-xCaxCrO3. The direct current (DC) four-probe technique measurement indicated that the electrical conductivities of specimens increased along with the increase of Ca2+ content (x), especially when x=0.3 and 0.4. The material (x=0.4, about 94% relative density) showed excellent electrical conductivities of 48 Scm-1 in air and 13 Scm-1 in H2 (purity 99.999%) at 700°C respectively, which is about 3 times as high as that of La0.7Ca0.3CrO3.

In order to develop interconnect ceramics for intermediate temperature solid oxide fuel cells (IT-SOFCs), perovskite compounds, Gd 1− x Ca x CrO 3 ( x =0∼0.3), were prepared by an auto-ignition process and characterized. XRD analysis indicated that a single perovskite phase was obtained as Ca 2+ content ( x value) was lower than 0.3, while a second phase appeared at x =0.4. The lattice parameters of the unit cell decrease with increasing the substitution Ca 2+ for Gd 3+ . The particle sizes of Gd 0.7 Ca 0.3 CrO 3 powders are in the range of 20∼50 nm observed by TEM. The powders exhibited better sintering ability and could reach 94.8% relative density at 1400 °C for 4 h in air. The DC four probe technique measurement indicated that the electrical conductivities of the specimens increased with increasing Ca 2+ content as x ⩽0.3 but remarkably dropped when x =0.4, which might be attributed to the formation of the second phase with lower conductivity in the materials. Gd 0.7 Ca 0.3 CrO 3 with a density of 94% showed an electrical conductivity of 24 Scm -1 in air and 7.5 Scm -1 in H 2 (99.999%) at 700 °C respectively, which is about 50% more than that of the commonly used lanthanum chromite (La 0.7 Ca 0.3 CrO 3 ). It will be suitable to be interconnect material for IT-SOFCs.