In order to evaluate the influence of different admixtures on the performance of cement stabilized macadam, the influence of fly ash, expansive agent, brucite fiber and alkali salt early strength agent on dry shrinkage, temperature shrinkage, compression and tensile properties of cement stabilized macadam mixture was studied by unconfined compressive strength test, dry shrinkage test, temperature shrinkage test and splitting test, respectively. The results show that the temperature shrinkage, dry shrinkage, unconfined compressive strength and Splitting strength of cement stabilized macadam with fly ash, expansive agent, brucite fiber and basic salt are greatly improved. ... Read more

A high demand for heating energy in winter, overheating in summer and visual discomfort are important issues in school buildings in the cold climate of China. This study presents the use of simulation–optimization tools to find the optimal trade-off between minimizing energy use for heating and lighting, reducing summer discomfort time and maximizing the Useful Daylight Illuminance (UDI_avg, between 100 and 2000 lx). Different spatial configurations were investigated, including a single-sided open corridor type, a single-sided enclosed corridor type and a double-sided corridor type school. The following passive design parameters were considered in the optimization analysis: orientation, room depth and corridor depth, window-to-wall ratio of different interfaces, glazing materials and shading types. The results of the optimization study show that the energy demand for heating and lighting can be reduced by 24–28% and summer thermal discomfort by 9–23% while the UDI_avg (100–2000 lx) can simultaneously increase by 15–63%. Considering all three aspects, the double-sided enclosed corridor type performs best due to its energy performance while the one-sided enclosed corridor type is the least suitable for the cold climate because of its relatively poor visual comfort quality. In addition, the passive design parameters should be carefully considered as each spatial configuration has its own optimal passive design parameters. ... Read more

This paper discusses the role of geometry parameters including building shape, window to wall ratio, room depth, and orientation on the energy use and thermal comfort of school buildings in cold climates of China. The annual total energy demand and summer thermal discomfort time were compared through computer simulations with DesignBuilder. Furthermore, a questionnaire was conducted that related to the students’ subjective preference for various building geometry parameters. Results showed that a maximum of 13.6% of energy savings and 3.8% of thermal comfort improvement when compared to the reference case could be achieved through variations in geometry parameters. The H shape performed the best when the building thermal performance and students’ preferences were considered, as well as the various design options for rchitects. Window to wall ratio, room depth, and orientation should also be carefully addressed in terms of different building types. The results of this study can serve as a reference for architects and school managers in the early design stages of schools in cold climates of China. ... Read more

Land developers play a key role in land-use and land cover change, as they directly make land development decisions and bridge the land and housing markets. Developers choose and purchase land from rural land owners, develop and subdivide land into parcel lots, build structures on lots, and sell houses to residential households. Developers determine the initial landscaping states of developed parcels, affecting the state and future trajectories of residential land cover, as well as land market activity. Despite their importance, developers are underrepresented in land use change models due to paucity of data and knowledge regarding their decision-making. Drawing on economic theories and empirical literature, we have developed a generalized model of land development decision-making within a broader agent-based model of land-use change via land markets. Developer's strategies combine their specialty in developing of particular subdivision types, their perception of and attitude towards market uncertainty, and their learning and adaptation strategies based on the dynamics of the simulated land and housing markets. We present a new agent-based land market model that includes these elements. The model will be used to experiment with these different development decision-making methods and compare their impacts on model outputs, particularly on the quantity and spatial pattern of resultant land use changes. Coupling between the land market and a carbon sequestration model, developed for the larger SLUCE2 project, will allow us, in future work, to examine how different developer's strategies will affect the carbon balance in residential landscapes. ... Read more