游离氧化钙对水泥性能的影响探析
摘要:游离氧化钙;水泥;安定性;强度
Abstract: contain harmful material such as free calcium oxide in cement, if the material content is too much, when mixing and pouring concrete, wrapped in vitreous membrane on the surface of the free lime has not completely broken, the inside of the calcium oxide particles and water role fully, after concrete hardening, moisture from the atmosphere into concrete, the free calcium oxide to absorb moisture in the air, gradually mature hydrated lime, volume expansion, fracture, osteoporosis, and the surface spalling, damage to concrete component, its excellent until the loss of load-carrying capacity. This article mainly discusses the causes of free lime and classification, and discusses in detail the free lime cement stability and intensity of the impact.
Abstract: the free lime; Cement; Stability; The intensity of
一、游离氧化钙概述
游离氧化钙(f-Cao)也叫游离石灰,为无色圆形颗粒,属等轴晶系。水泥熟料矿物主要是在高温下固相反应生成,反应的完全程度受到生料的配比,细度和混合均匀程度,烧成温度及烧成带停留时间等条件的影响,氧化钙与氧化硅、氧化铝、氧化铁的化学反应不可能很完全,或多或少地将剩余一些氧化钙未被吸收化合。
熟料中的游离氧化钙经1400-1450℃高温煅烧(俗称死烧石灰),结构致密,且被包裹在熟料矿物中,水分子很难进入其颗粒内,所以,遇水反应缓慢,其水化反应式为:
CaO+H2O=CaO(OH)2
CaO与水反应生成CaO(OH)2时,固相体积增大到1.98倍,如果这个过程在水泥硬化之前完成,则对混凝土不会产生危害。但水泥中的游离氧化钙在常温下水化作用缓慢,至水泥混凝土硬化后较长一段时间(一般需3至6个月)内才能完全水化。水化后由于固相体积增大一倍,在已经硬化的水泥石内部产生局部膨胀,会使水泥凝土强度大大下降,严重时导致建筑物开裂或崩溃。
二、游离氧化钙的产生原因及分类
(一)轻烧游离氧化钙
由于来料量不稳或塌料、掉窑皮,或燃料成分变化或火焰形状不好,使部分、
游离氧化钙对水泥性能的影响探析
摘要:游离氧化钙;水泥;安定性;强度
Abstract: contain harmful material such as free calcium oxide in cement, if the material content is too much, when mixing and pouring concrete, wrapped in vitreous membrane on the surface of the free lime has not completely broken, the inside of the calcium oxide particles and water role fully, after concrete hardening, moisture from the atmosphere into concrete, the free calcium oxide to absorb moisture in the air, gradually mature hydrated lime, volume expansion, fracture, osteoporosis, and the surface spalling, damage to concrete component, its excellent until the loss of load-carrying capacity. This article mainly discusses the causes of free lime and classification, and discusses in detail the free lime cement stability and intensity of the impact.
Abstract: the free lime; Cement; Stability; The intensity of
一、游离氧化钙概述
游离氧化钙(f-Cao)也叫游离石灰,为无色圆形颗粒,属等轴晶系。水泥熟料矿物主要是在高温下固相反应生成,反应的完全程度受到生料的配比,细度和混合均匀程度,烧成温度及烧成带停留时间等条件的影响,氧化钙与氧化硅、氧化铝、氧化铁的化学反应不可能很完全,或多或少地将剩余一些氧化钙未被吸收化合。
熟料中的游离氧化钙经1400-1450℃高温煅烧(俗称死烧石灰),结构致密,且被包裹在熟料矿物中,水分子很难进入其颗粒内,所以,遇水反应缓慢,其水化反应式为:
CaO+H2O=CaO(OH)2
CaO与水反应生成CaO(OH)2时,固相体积增大到1.98倍,如果这个过程在水泥硬化之前完成,则对混凝土不会产生危害。但水泥中的游离氧化钙在常温下水化作用缓慢,至水泥混凝土硬化后较长一段时间(一般需3至6个月)内才能完全水化。水化后由于固相体积增大一倍,在已经硬化的水泥石内部产生局部膨胀,会使水泥凝土强度大大下降,严重时导致建筑物开裂或崩溃。
二、游离氧化钙的产生原因及分类
(一)轻烧游离氧化钙
由于来料量不稳或塌料、掉窑皮,或燃料成分变化或火焰形状不好,使部分、