POWDERY ADDITIVE FOR PREMIXED REPAIR MORTAR, PREMIXED REPAIR MORTAR, AND CEMENT HARDENED BODY

PROBLEM TO BE SOLVED: To provide an additive for premixed repair mortar having high storage stability, where the mortar is prevented from drying cracks by manifestation of a drying shrinkage reduction effect, manifests sufficient strength, provides a plasterer with excellent workability, and does not interfere with durability of a concrete structure.SOLUTION: The powdery additive for premixed repair mortar comprises the following component (A) and component (B), where a mass ratio of component (A) and component (B) is 9:1 to 80:20. Component (A) is inorganic powder obtained by adsorption of a polyoxyalkylene derivative (a2), which is a liquid at 25°C, to inorganic powder (a1) in a mass ratio as (a1):(a2) of 20:80 to 60:40, where the polyoxyalkylene derivative is selected from polyoxyalkylene derivatives represented by formula [I]: RO-(AO)n-Rand represented by formula [II]: HO-(AO)m-H. Component (B) is a cationic surfactant, which is a dimethyl alkyl benzyl quaternary ammonium salt.SELECTED DRAWING: None 【課題】乾燥収縮低減効果を発現することで乾燥ひび割れを抑制し、十分な強度を発現し、左官の作業性に優れ、コンクリート構造物の耐久性を損なわない保存安定性の高いプレミックス補修モルタル用添加剤の提供。【解決手段】（Ａ）成分及び（Ｂ）成分を含有し、（Ａ）成分と（Ｂ）成分の質量比が９：１〜８０：２０であるプレミックス補修モルタル用粉体添加剤。（Ａ）成分：無機微粉末（ａ１）に、２５℃で液体のポリオキシアルキレン誘導体（ａ２）を質量比（ａ１）：（ａ２）＝２０：８０〜６０：４０で吸着させた無機微粉末であって、ポリオキシアルキレン誘導体が、式〔Ｉ〕及び式〔ＩＩ〕で表されるポリオキシアルキレン誘導体から選ばれる。Ｒ１Ｏ−（ＡＯ）ｎ−Ｒ２〔Ｉ〕ＨＯ−（ＡＯ）ｍ−Ｈ〔ＩＩ〕（Ｂ）成分：カチオン界面活性剤で、ジメチル・アルキル・ベンジル４級アンモニウム塩。【選択図】なし