外掺不同煅烧工艺MgO膨胀剂对水工混凝土安定性的影响

The Influence of Different Calcining Process MgO Expansive Agent on the Soundness of Hydraulic Concrete

目前市面上轻烧MgO膨胀剂大多为采用回转窑、立窑和沸腾炉进行煅烧而成。为满足水工大坝对外掺MgO膨胀剂混凝土安定性的要求和水工混凝土中外掺MgO膨胀剂技术的推广,本文对三种煅烧工艺下MgO膨胀剂在水工混凝土中的压蒸安定性进行了研究。结果表明:无论采用何种煅烧工艺生产的MgO膨胀剂(活性指数120 s/200 s),水工混凝土的压蒸膨胀率值均满足规范要求;采用沸腾炉、回转窑和立窑煅烧工艺生产的MgO膨胀剂在水工混凝土中压蒸安定性的最大掺量不同;掺加回转窑生产的MgO膨胀剂的水工混凝土的抗压强度高于掺加立窑和沸腾炉生产的MgO膨胀剂的水工混凝土。研究结果可供外掺MgO膨胀剂水工混凝土在实际工程应用参考。

At present, the light-burned MgO expansive agent on the market is basically calcined by rotary kiln, vertical kiln and boiling furnace.In order to meet the requirements of the hydraulic dam for the soundness of concrete admixed with MgO expansive agent, this paper studies the soundness of the MgO expansive agent in hydraulic concrete under three calcining processes.The results showed that regardless of MgO expansive agent(activity index 120 s/200 s) produced by what kind of calcining processes, the autoclave expansion of hydraulic concrete met the specification requirement;the autoclave soundness maximum amount of hydraulic concrete mixed with MgO expansive agent produced by calcining process of boiling furnace, rotary kiln and vertical kiln wss different;the compressive strength of hydraulic concrete mixed with MgO expansive agent produced by rotary kiln was higher than that of hydraulic concrete mixed with MgO expansive agent produced by vertical kiln and boiling furnace.The research results can be used for reference to hydraulic concrete with MgO expansive agent in practical engineering.