Construction Technique Analysis and Improvement for Rammed Earth Wall of Rural Houses in Hanzhong

Rammed earth wall technique is one of the local widespread traditional construction methods, and it has superior physical property and ecological protection characteristic. When contemporary raw-soil building is replaced by industry building, the hometown building culture is perishing gradually. In order to inherit and develop the Hanzhong local building, rammed earth wall in Taiyangling and Cangshe hometown is investigated, and the characteristics and construction techniques of the local rammed earth wall are concluded. According to the construction problems, the improvement suggestions are put forward, which establishes the foundation to investigate rammed earth wall further, and guide Rural House construction.

Engineering Properties of Unstabilized Rammed Earth with Different Clay Contents

The physical and mechanical properties of unstabilized rammed earth with different clay contents were studied, which could provide a theoretical basis for the understanding of mechanical properties of unstabilized rammed earth and improve the construction design method and specification of RE buildings for sustainable development. The experimental results show that clay content has significant influences on the engineering properties of unstabilized rammed earth. For the fine-grained soil, the liquid limit, plastic limit and plasticity index increase gradually with the increase of the clay content. The influence of clay content on the optimum moisture content compared with the maximum dry density is more significant. The mechanical properties of unstabilized rammed earth are significantly affected by the clay content. There exist good linear relationships, which can be used for the mutual verification or calculation among the mechanical properties. An empirical model of unconfined compression strength with the FA/CA ratio as the main parameter is established, and the UCS may obtain the maximum with a FA/CA ratio of 5.77.

RECOMMENDATIONS FOR THE SELECTION,STABILIZATION,AND COMPACTION OF SOIL FOR RAMMED EARTH WALL CONSTRUCTION

Rammed earth possesses environmental advantages over most other competing construction materials.However,if it is to be more routinely used in the construction of modern,sustainable buildings,its material properties and produc-tion processes must be properly quantified.This paper proposes practical recommendations for soil selection,stabilizer treatment,and on-site compaction for rammed earth,based on a recent set of 219 stabilization experiments.The pur-pose of the recommendations is to maximize the probability of constructing rammed earth walls that meet or exceed a compressive strength criterion of 2 MPa.The recommendations cover:(1)Quantifying the natural soil properties of linear shrinkage and texture in a staged sequence in order to identify suitable soils to stabilize(and to reject unsuit-able soils);(2)Quantifying the amounts of cement and/or lime to be added to the selected soil according to the values of soil properties measured;and(3)Quantifying the forces involved in on-site compaction of stabilized soil(for both manual and pneumatic ramming),and relating these to laboratory-based test standards.Although the recommenda-tions need to be tested and verified/refined using new data,their initial application to rammed earth construction situations in Australia indicates that they have predictive utility.Further research will also indicate the degree of applicability of the recommendations to the production of compressed earth bricks.

Research on the historical and cultural value of and protection strategy for rammed earth watchtower houses in Chongqing,China

Chinese watchtower houses are part of the unique human cultural heritage of the world’s vernacular architectures.Many earthen manor watchtower houses in Chongqing,China,have absorbed the characteristics of other tower houses across the country and have brought together various types of watchtower construction techniques.They are important connection points for the integrity of the Chinese watchtower house as a comprehensive architectural cultural heritage system.They can be a typical sample of Chinese Han classical towers.These buildings are indispensable parts of the Chinese residential watchtower system and have important cultural protection value.However,due to the general lack of excavation and attention to their historical and cultural value,these buildings are on the verge of disappearing.Although they have lost their original architectural functions,they have important value in terms of their building materials,technical composition and artistic modelling.They can stimulate special emotional resonance and become an important bridge that maintains the cultural connection between ancient and modern humans.Therefore,discussing the historical and cultural value of Chongqing rammed earth watchtower houses,the strategy for heritage protection and utilisation is of far-reaching signifcance for Chinese watchtower dwellings.

Structure creation in earthen construction materials:information from dry soil mixtures

There is increasing interest in the use of earthen construction materials,such as rammed earth,due to their inherent sustainability.These materials have been used by man for thousands of years and some of the earliest examples can be found in China.Features of the structures of these materials arise from the means of production.In particular,in situ earthen construction materials exhibit strong anisotropy due to their layered nature.A more subtle structure effect arises from the way that the earth mixture is deposited.This paper reviews and discusses stratification effects in dry soil mixtures,including some original experimental work,and indicates some links between the features of the dry mixtures and earthen construction materials.Improved understanding of the physical processes in play will allow more accurate specification of these materials in the future,and hence spread their use.

The protection project of Hanyuan Hall and Linde Hall of the Darning Palace

This paper expounds the consideration to the design of protection and exhibition of Hanyuan Hall and Linde Hall of the Daming Palace. Based on in-depth study on their existing conditions after archeological excavation, and in combination with comprehensive considerations in terms of the protection of the main body of sites, the restoration research of existing bases and superstructures, the requirement of site open exhibition, etc., it proposes the design to restore the rammed earth bases by surrounding them with bricks and stones or rammed earth. Besides the protection and exhibition of the site of Hanyuan Hall bases, it also integrates the features of landform there to design the protection and exhibition of brick and tile kiln of Tang Dynasty within the relic area. Under the condition at that time, a semi-underground small exhibition center is designed by taking advantage of the height difference of base side slopes, satisfying the requirement of exhibition, and meanwhile preserving the overall landscape of the site. The integration of the design of protection project with archeology as well as the science and technology of heritage preservation is a brand-new probe into site protection design.