Mortar to Repair Rammed-Earth Walls’ Surfaces: Do we still Need it?

A rammed-earth technique has been echoed worldwide due to being conceived not only as an environment-friendly method of construction but also standing as an alternative method to arguably replacing cement. The technique however shows several pitfalls. One concerns the lengthy process of curing upon erecting the rammed-earth walls due to the low process of a chemical reaction occurred throughout the curing stage. A second bias followed from the slow curing and concerns the degradation accentuated at the outer wall’s texture, particularly at the edges, due to effects of the weather cycle. These drawbacks have been observed while accomplishing a funded research project. This article has at its stake remedying the above pitfalls. A natural sandy limestone shows a low percentage of calcium carbonate needed for a cohesive mixture. The method suggested here is based on an experiment that uses minerals of the fruits’ and vegetables’ waste as a binding substance. Curing time in this method has been reduced to the half. It is also suggested here that each stage has its importance, including mixing the soil particles dry and wet, compacting the moistened soil mixture, a well-made formwork and curing, towards remedying the above pitfalls.

Evaluation of the Thermal Comfort and Energy Demand in a Building with Rammed Earth Walls in Spain: Influence of the Use of In Situ Measured Thermal Conductivity and Estimated Values

This paper describes the influence of thermal parameters—conductivity, transmittance, and thermal mass—in the estimation of comfort and energy demand of a building with rammed earth walls, and consequently, the compliance with standards. It is known that nominal design data does not match in situ measured values, especially in traditionally constructed buildings. We have therefore monitored a room in a building with rammed earth walls, designed a computerised model, and compared four different alternatives where we have changed the value for the thermal conductivity (in situ vs. estimated) and the consideration of thermal mass. When we then analyse the compliance with the Spanish energy saving code, using measured values would result in lower differences with the standards’ limits and even comply with the global thermal transmittance (K-value) requirement. This would mean a more realistic approach to the restoration of traditional buildings leading to the use of thinner and more suitable insulation and retrofitting systems, encouraging the use of rammed earth in new buildings, and therefore reducing the carbon footprint due to materials used in construction. Results show that the building model that uses in situ values and considers thermal mass (S1) is closer to reality when assessing thermal comfort. Finally, using nominal data would result in requiring 43% more energy in the selected winter period and 102% more energy in the selected summer period to keep the same comfort conditions as in the alternative where measured values are used.