Search

JP-7857248-B2 - Ultra-fast hardening mortar material for grouting, hardened mortar body

JP7857248B2JP 7857248 B2JP7857248 B2JP 7857248B2JP-7857248-B2

Inventors

  • 高木 聡史

Assignees

  • デンカ株式会社

Dates

Publication Date
20260512
Application Date
20230331

Claims (8)

  1. It contains cement, calcium aluminate (excluding C11A7 ・ CaF2 ), and gypsum. The CaO/ Al₂O₃ molar ratio of the calcium aluminate is 1.5 to 3.0. The vitrification rate of the calcium aluminate is 80% or more. An ultra-fast-setting mortar material for grouting, with expansion rates of 0.005-0.5%, 0.01-0.75%, and 0.015-1.0% at 3, 7, and 28 days of age, respectively.
  2. The ultra-fast-setting mortar material for grout according to claim 1, wherein the air content after mixing is 0-5%.
  3. The ultra-fast-setting mortar material for grout according to claim 1 or 2, wherein the flow value after mixing is 190 to 220 mm.
  4. The ultra-fast-setting mortar material for grout according to claim 1 or 2, wherein the flow time through the J 14 funnel after mixing is 6 to 10 seconds.
  5. The ultra-fast-setting mortar material for grout according to claim 1 or 2, further comprising a foaming agent.
  6. The ultra-fast-setting mortar material for grout according to claim 1 or 2, further comprising an antifoaming agent.
  7. The ultra-fast-setting mortar material for grout according to claim 1 or 2, further comprising one or more water-reducing agents selected from the group consisting of lignin-based water-reducing agents, melamine-based water-reducing agents, and naphthalene sulfone-based water-reducing agents.
  8. A hardened mortar body made using the ultra-fast-setting mortar material for grouting described in claim 1 or 2.

Description

This invention relates to an ultra-fast-setting mortar material for grouting and a hardened mortar body. Grout is used in the construction of underground structures, the installation of bridge bearings, the installation of various types of machinery, and the filling of gaps between walls and columns in seismic reinforcement. In recent years, with the increasing demand for streamlined construction, there is a need for mortar materials that possess ultra-fast hardening properties, self-compacting capabilities, and self-leveling properties. Mortar materials, due to volume reduction during cement hydration or drying, pose a risk of cracking and reduced adhesion to existing structures when used as grout. Cracks not only detract from the aesthetics but also pose a risk of adverse effects on the structural stability, waterproofing, and watertightness. Therefore, in order to compensate for cement shrinkage, suppress crack formation, and maintain adhesion to the structure, various types of expanders are used, such as 3CaO・3Al₂O₃・CaSO₄ ( hauyne ), calcium sulfoaluminate-based materials mainly composed of CaSO₄ and CaO (hauyne-based expanders), lime-based materials mainly composed of free lime (lime-based expanders), and expanders containing free lime, hydraulic substances, and gypsum. As materials with excellent ultrafast hardening properties, for example, ultrafast hardening cement compositions are known in which metal sulfates or fly ash are added to calcium aluminates or gypsum to ensure fluidity (Patent Documents 1-3). Furthermore, ultrafast-setting cement containing calcium aluminate, gypsum, and lithium carbonate (Patent Document 4), and mortar containing Portland cement, calcium aluminate, anhydrous gypsum, lithium carbonate, and slaked lime have also been proposed (Patent Document 5). Japanese Patent Application Publication No. 03-12350Japanese Patent Application Publication No. 01-230455Japanese Patent Application Publication No. 11-139859Japanese Patent Application Publication No. 01-290543Japanese Patent Publication No. 2005-75712 The following describes in detail one embodiment of the present invention, but the present invention is not limited to this embodiment. In this specification, "%" and "parts" refer to mass unless otherwise specified. [Ultra-fast hardening mortar material for grouting] The present invention provides an ultra-fast-setting mortar material for grouting that comprises cement, calcium aluminate, and gypsum, and has expansion rates of 0.005 to 0.5%, 0.01 to 0.75%, and 0.015 to 1.0% at 3, 7, and 28 days of age, respectively. Preferably, the expansion rate is 3 days ≤ 7 days ≤ 28 days of age. The ultra-fast-setting mortar material for grouting can be used as grout by mixing it with water, and by adjusting the initial expansion rate to be within a predetermined range, the long-term expansion rate can be appropriately controlled. This prevents damage to structures when used as grout. Long-term refers to at least 60 days of age. Furthermore, the expansion rate in this invention is measured according to the method specified in JIS A 6202:2017 "Expanding Agents for Concrete," Annex A "Test Method for Expansion of Expansible Agents with Mortar." The ultra-fast-setting mortar material for grouting has an expansion rate of 0.005 to 0.5% at 3 days of age, preferably 0.01 to 0.4%, more preferably 0.05 to 0.3%, and even more preferably 0.1 to 0.2%. If the expansion rate at 3 days of age is less than 0.005%, the long-term expansion rate may be insufficient, and if it exceeds 0.5%, the long-term expansion rate may be excessive. The ultra-fast-setting mortar material for grouting has an expansion rate of 0.01 to 0.75% at 7 days of age, preferably 0.02 to 0.5%, more preferably 0.08 to 0.4%, and even more preferably 0.12 to 0.3%. If the expansion rate at 7 days of age is less than 0.01%, there is a risk of insufficient long-term expansion, and if it exceeds 0.75%, there is a risk of excessive long-term expansion. The ultra-fast-setting mortar material for grouting has an expansion rate of 0.015 to 1.0% at 28 days of age, preferably 0.03 to 0.6%, more preferably 0.1 to 0.5%, and even more preferably 0.16 to 0.4%. If the expansion rate at 28 days of age is less than 0.015%, there is a risk of insufficient long-term expansion, and if it exceeds 3.5%, there is a risk of excessive long-term expansion. The ultra-fast-setting mortar material for grouting preferably has an air content of 0-5% after mixing, more preferably 0-4%, and even more preferably 0-3%. When the air content after mixing is within the above range, the strength development is improved. The air content in this invention was measured in accordance with the method specified in JIS A 1116:2019 "Test method for unit volume mass of fresh concrete and test method for air content by mass (mass method)." The ultra-fast-setting mortar material for grouting preferably has a flow value of 170 to 320 mm after mixing, more preferably 190 to 250 mm, and eve