Evaluation of soil-cement blocks for sustainability and habitability in accordance to the Brazilian standard ABNT NBR 15575

ABSTRACT The building sector is responsible for significant consumption of natural resources. Sustainable buildings contributes to the reduction of environmental impacts such as energy consumption, soil, and water and air pollution. In this scenario, raw soil as a building material has become an alternative for the development of sustainable buildings. Raw soil is cured without burning. Raw soil mixed with Portland cement, pressed and stabilized produces soil-cement blocks and they are already regulated by the Brazilian technical standards association (Associação Brasileira de NormasTécnicas – ABNT) and possesses many advantages related to its manufacturing and use. To increase its acceptance and verify its efficiency as a building material for social housing, it is necessary to investigate its properties and performance. The present study aimed to evaluate the performance of an external vertical sealing system composed of hollow blocks of soil-cement without structural function for social housing, following determinations of ABNT NBR 15575, focusing on the requirements of habitability and sustainability. It was analysed tightness against rainwater and water permeability, habitability requirements, and durability, sustainability requirement, through heat action and thermal shock testings. The system met limits set by standards for tightness against rainwater and heat action and thermal shock, but not for water permeability. The vertical sealing system composed of hollow blocks of soil-cement has potential for application in the construction, but there is still need for more studies on the system.

摘要
建筑行业是自然资源大量消耗的核心领域之一。可持续建筑有助于减少能源消耗、土壤破坏、水污染及空气污染等各类环境影响。在此背景下，生土作为一种建筑材料，已成为可持续建筑发展的可行替代方案。生土无需焙烧即可进行养护处理：将生土与硅酸盐水泥混合后经压制与稳定化处理，可制得土水泥砌块（soil-cement blocks），该材料已纳入巴西标准技术协会（Associação Brasileira de Normas Técnicas，简称ABNT）的监管范畴，且在生产与使用环节具备诸多优势。为提升该材料的市场接受度，并验证其作为保障性住房建筑材料的性能，有必要对其各项属性与应用表现展开研究。
本研究旨在依据巴西标准ABNT NBR 15575的相关规定，评估用于保障性住房的、无结构承重功能的土水泥空心砌块外部垂直密封系统的性能，研究重点聚焦居住性与可持续性相关要求。本研究通过热作用试验与热冲击试验，对该系统的抗雨水密封性、透水性、居住性要求、耐久性及可持续性要求展开了分析。结果显示，该系统在抗雨水密封性、热作用及热冲击方面符合标准限值要求，但透水性指标未达标。由土水泥空心砌块构成的垂直密封系统具备建筑应用潜力，但仍需针对该系统开展更多后续研究。