Fundamental Study on the Effectiveness of Resin Emulsion in Improving the Bond Strength at Horizontal Joints of Concrete

树脂乳液提高混凝土水平缝粘结强度效果的基础研究

• 批准号: 12650456
• 负责人: YAMAMOTO Yasuhiko
• 金额: $ 2.3万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650456/
• 关键词: resin emulsion; horizontal joint; successively layered concretes; construction joint; cold-joint; bonding strength; breeding water; 打継ぎ強度; 水平打継目; コンクリート; ポリマーセメント

Experimental study was conducted to examine both the reliability of widely-spread easy joining method of spraying resin emulsions on the finished surface of fresh concrete and its applicabity as an emergency measure for preventing the occurrence of cold-joints in concrete structures. Main conclusions are as follows.1. Even in the portions of sections where consolidation of concrete is made only by the propagated vibration from internal vibrators, cold-joint may not occur when the joining of concrete is made while the penetration resistance of lower concrete is less than 0.1 N/mm^2.2. When the spraying of resin emulsions is made without removing the excess breeding water on the joining surface, the bonding strength at joints is badly damaged.3. When the spraying of resin emulsions is made after the removal of bleeding water, the joining strength of concretes is improved compared with the case where no treatment is made. However, the improved strength is not higher than the strength at joints treated properly by conventional procedures.4. The bonding strength at horizontal construction joints can be improved when the mixture of resin emulsion and cement is spreaded at the rate of about 1 kg/m^3 over the surface of lower concrete, which has been strengthened by spraying resin emulsions.5. Spraying resin emulsions is not a reliable method for the prevention of cold-joints.

通过试验研究，验证了在新拌混凝土成品表面喷涂树脂乳液这一广泛应用的简易连接方法的可靠性及其作为防止混凝土结构发生冷缝的应急措施的适用性。主要结论如下：1。即使在仅通过内部振动器的传播振动进行混凝土固结的截面部分，当下部混凝土的穿透阻力小于0.1 N/mm^2.2时，混凝土的连接也可能不会发生冷缝。2 .在喷涂树脂乳液时，如果不去除接合面上多余的繁殖水，会严重破坏接合处的结合强度。除放水后进行树脂乳液喷涂，与不进行处理相比，混凝土的粘结强度得到提高。然而，改进后的强度并不比常规方法处理后的强度高。4 .将树脂乳液与水泥的混合料以1 kg/m^3左右的速度涂抹在下层混凝土表面，通过树脂乳液的喷洒加固，可提高水平施工缝的粘结强度。喷涂树脂乳液并不是预防冷接头的可靠方法。

项目成果

山本泰彦, 杉本宣博: "樹脂エマルションによるコールドジョイント防止策に関する研究"コンクリート工学年次論文集. (投稿予定)「土木学会・年次学術講演会」(一部分を発表予定).

山本泰彦、杉本信宏：《利用树脂乳液防止冷缝的措施研究》年度混凝土工程论文集（待提交）《日本土木工程学会年度学术讲座》（部分发表）。

山本泰彦, 杉本宣博: "振動のみが伝達する部位でのコールドジョイントの発生条件に関する研究"コンクリート工学年次論文集. (投稿予定).

Yasuhiko Yamamoto、Nobuhiro Sugimoto：“仅传输振动的区域中出现冷缝的条件的研究”，年度混凝土工程学会论文集（待提交）。