PERCEPTIONS OF COMPRESSED EARTH BLOCK AMONG RESIDENTIAL CONTRACTORS IN NORTH CAROLINA:AN EXPLORATORY EVALUATION

Compressed carth blocks(CEB)retain the environmental benchts of traditional carthen construction while reducing labor costs and project duration.Despitc these advantages,CEB remains a niche matcrial in the U.S.This study explored residential contractors'perceptions of CEB as a barrier to adoption.A survey was distributed to residential contractors in the North Carolina Picdmont,a region that possscs ideal soil for carthen buildings.Construction professionals in states where carthen construction has a larger market share(New Mexico,Oklahoma,and Texas)were also qucricd for comparison.Respondents with no CEB expcrience provided significantly(p<0.05)lower levcls of agreement with statements that CEB is cost ffective,struc-turally safe and acsthetically appcaling than did respondents with CEB experience.Intervicws conducted with an cxperienced CEB contractor and a manufacturer ol CEB production cquipment provided additional insight and informed the quantita-tive results.Findings represcnt an important stcp in exploring stakcholder perceptions as an impediment to the adoption of non-conventional matcrials like CEB in the residential construction scctor.Educating the next gencration of builders and home-owners is a key component for the implementation of CEB construction.Educational strategics,study limitations and opportunitics for further rescarch arc discussed.

Optimisation of Thermal Comfort of Building in a Hot and Dry Tropical Climate: A Comparative Approach between Compressed Earth/Concrete Block Envelopes

Compressed earth blocks (CEB) are an alternative to cement blocks in the construction of wall masonry. However, the optimal architectural construction methods for adequate thermal comfort for occupants in hot and arid environments are not mastered. This article evaluates the influence of architectural and constructive modes of buildings made of CEB walls and concrete block walls, to optimize and compare their thermal comfort in the hot and dry tropical climate of Ouagadougou, Burkina Faso. Two identical pilot buildings whose envelopes are made of CEB and concrete blocks were monitored for this study. The thermal models of the pilot buildings were implemented in the SketchUp software using an extension of EnergyPlus. The models were empirically validated after calibration against measured thermal data from the buildings. The models were used to do a parametric analysis for optimization of the thermal performances by simulating plaster coatings on the exterior of walls, airtight openings and natural ventilation depending on external weather conditions. The results show that the CEB building displays 7016 hours of discomfort, equivalent to 80.1% of the time, and the concrete building displays 6948 hours of discomfort, equivalent to 79.3% of the time. The optimization by modifications reduced the discomfort to 2918 and 3125 hours respectively;i.e. equivalent to only 33.3% for the CEB building and 35.7% for the concrete building. More study should evaluate thermal optimizations in buildings in real time of usage such as residential buildings commonly used by the local middle class. The use of CEB as a construction material and passive means of improving thermal comfort is a suitable ecological and economical option to replace cementitious material.

Thermal energy performance of compressed earth building in two different cities in Moroccan semi-arid climate

The assessment of the thermal energy performance of earth-based buildings with respect to the semi-arid Mediter-ranean climate of Morocco is scarce,even if the country is historically known for its earthen dwellings.According to this need,this work aims to understand and evaluate the indoor thermal comfort and energy performances of passive building in two different locations.We have used EnergyPlus modeling tool and in addition,the moni-tored ten-day indoor temperatures in two different thermal zones in the test prototype to justify the empirical validation of Building Energy Model.The findings demonstrate,the use of compressed earth blocks coupled with passive design strategies provides better comfort and great sustainability.Thus,the summer discomfort hours are reduced about 12%for both cities compared to conventional building.However,the combination of semi-arid climate-responsive passive design has allowed to reach a thermal energy intensity reduction difference from 20 to 65 kWh.m^(-2).y^(-1).