Influence of additives on strength enhancement and greenhouse gas emissions of pre-cast lime-based construction products  

作　　者：F.J.O’Flaherty F.J.Khalaf V.Starinieri 

机构地区：[1]Centre for Infrastructure Management,Materials and Engineering Research Institute,I2RI,Sheffield Hallam University,Sheffield S11WB,UK

出　　处：《Low-carbon Materials and Green Construction》2023年第1期347-364,共18页低碳材料与绿色建造（英文）

基　　金：supported by the Iraqi Ministry of Higher Education and Scientific Research and Iraqi Cultural Attache in London,who supported the research studies for F.J.Khalaf.

摘　　要：Strength properties of laboratory scale lime-based samples enhanced with additives such as nanomaterials(nanofibrillated cellulose,nanosilica,nanoclay,expanded graphite),hemp&glass fibres,hemp shiv and polyvinyl acetate(PVAc)are determined.Samples were cured for 26 days in air at 20℃/60%RH after casting before being oven dried for a further two days at 50℃(28 days total).Results show that the nanomaterials on their own had a mixed effect on the strength although nSiO_(2) as a solo additive performed exceptionally well.The combination of fibres in conjunction with PVAc also greatly enhanced the strength due to increased bond between the fibres and the matrix.In addition,Greenhouse Gas emissions(GHG,kgCO_(2)eq)of an arbitrary block was determined for all composites and compared to the GHG of a commonly used lightweight aerated concrete block.Comparison of the normalised compressive strengths to the different loading conditions as outlined in BS EN 8103 shows that a more widespread use of pre-cast lime composites is possible and without unduly increasing GHG emissions.本文测定了纳米材料(如:纳米纤丝化纤维素、纳米二氧化硅、纳米黏土、膨胀石墨)、大麻纤维和玻璃纤维、大麻杆和聚醋酸乙烯酯(PVAc)等添加剂对实验室尺度的石灰基试件强度的提升作用。试件的养护制度为在20℃和相对湿度60%下养护26天,之后在50℃烘箱中干燥2天(共28天)。试验结果表明,虽然纳米二氧化硅(nSiO_(2))作为单一添加剂的效果很好,但同时掺加多种纳米材料对试件强度存在综合影响。PVAc可以增强纤维与基体之间黏结作用,因此将纤维与聚醋酸乙烯酯(PVAc)复合使用能明显提高强度。此外,本文测定了所有复合材料砌块的温室气体排放量(GHG,kgCO_(2)eq),并将其与普通轻质加气混凝土砌块的GHG进行比较。根据BS EN 8103标准,将不同加载条件下的试件抗压强度进行归一化并做比较,其结果表明,更广泛地使用预制石灰基复合材料具有可行性,且不会过度增加温室气体排放量。

关 键 词：Hempcrete NANOMATERIALS Hemp shiv&fibre PVAC Glass fibre Greenhouse gas 

分 类 号：TB34[一般工业技术—材料科学与工程]