摘要
氯氧镁水泥(MOC)具有抗冻性好和抵抗盐卤腐蚀的特点。研究MOC用作高寒盐碱地区公路工程无机结合料稳定材料的可行性,探讨原料配比对MOC稳定材料抗压强度的影响规律。制作试件,测定试件的无侧限抗压强度并分析物相组成。结果表明:卤水浓度较低(<7.48%)时,活性MgO/MgCl_2物质的量比(Mg/Cl比)较大,MOC稳定砾石土的主要水化产物是Mg(OH)_2,无侧限抗压强度较低;卤水浓度升高(>9.35%)时,Mg/Cl比降低,水化产物中出现3Mg(OH)_2·MgCl_2·8H_2O(P318)和5Mg(OH)_2·MgCl_2·8H_2O(P518);主要水化产物为P318时无侧限抗压强度升高,主要水化产物为P518时无侧限抗压强度最高。轻烧镁粉掺量越大,水化产物越多,MOC稳定材料的无侧限抗压强度越大。MOC稳定材料的无侧限抗压强度决定于物相组成;卤水浓度、Mg/Cl比、轻烧镁粉掺量和卤水掺量是物相组成的重要影响因素。MOC稳定材料产生强度的机制包括活性MgO的水化作用及其水化产物的碳化作用、MgCl_2·6H_2O的结晶作用、填充作用、机械压实和离子交换作用。
Magnesium oxychloride cement（MOC） had the inherent quality of good resistance to brine corrosion and frost.The objectives of this study were to investigate the feasibility of using MOC as a stabilizing material of highway pavement structure in saline and cold area as well as the influence of mix proportion of raw materials on the unconfined compressive strength（UCS） of gravel soil solidified by MOC.The UCS and the mineral composition of specimens were analyzed,respectively.The results show that the solidified gravel soil with a larger ratio of active Mg O/MgCl2（Mg/Cl） is mainly Mg（OH）2 in hydrated products and has the low UCS when the brine concentration is less than 7.48%.When the brine concentration increases,3 Mg（OH）2·MgCl2·8 H2O（P318） and 5 Mg（OH）2·MgCl2·8 H2O（P518） appear in the solidified mixture with the decreasing of Mg/Cl.The solidified gravel soil has higher UCS when the major hydrated product is P318 rather than Mg（OH）2,while the highest UCSis obtained when P518 appears.The greater the light-burn magnesia content,the more hydrated products and the higher UCS of solidified gravel soil.The UCS of MOC solidified gravel soil is determined by the mineral composition.The enhancement mechanisms of UCS of gravel soil solidified by MOC are attributed to the hydration of active Mg O,carbonization of hydrated products,crystallization of MgCl2·6 H2O,filling effect,mechanical compaction effect,and ion exchange effect.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2017年第A02期4158-4166,共9页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(U1507120)
青海省重大科技专项(2014–GX-A2A)
青海省自然科学基金(2015–ZJ–949Q)~~
关键词
建筑材料
氯氧镁水泥
稳定砾石土
原料配比
物相组成
无侧限抗压强度
building material
magnesium oxychloride cemem（MOC）
solidified gravel soil
mix proportion
mineral composition
unconfined compressive strength（UCS）
