A curable resin composition having an initial viscosity change ratio defined by the following relational expression 1 in a range of 1.1 to 5.0, and having an initial viscosity change ratio defined by the following relational expression 2 of 10 or more, wherein in the following relational expressions 1 and 2, V 1 is in a range of 100 Ns/m 2 (100,000 cP) to 500 Ns/m 2 (500,000 cP), V 2 is 2,000 Ns/m 2 (2,000,000 cP) or less, and V 3 satisfies 5,000 Ns/m 2 (5,000,000 cP) or more: Initial viscosity change ratio = V 2 / V 1 Initial viscosity change ratio = V 3 / V 1 wherein, V 1 is an initial viscosity, which is a viscosity value as measured at room temperature within 60 seconds after mixing main agent and curing agent components of the resin composition, V 2 is a viscosity value measured after leaving the resin composition, in which V 1 has been measured, at room temperature for 5 minutes and V 3 is a viscosity value measured after leaving the resin composition, in which V 1 has been measured, at room temperature for 60 minutes, and when V 1 and V 3 are measured in a shear rate range of 0.01 to 10.0/s using a rheological property measuring device (ARES), they are viscosity values measured at a point of 2.5/s, wherein the resin composition is a room temperature curing type resin composition and comprises a two-component urethane-based resin composition, wherein the two-component urethane-based resin composition comprises an ester-based polyol resincontaining main composition part, a polyisocyanate-containing curing agent composition part, and a filler, and the ester-based polyol resin is an amorphous polyol, in which a crystallization temperature (Tc) and a melting temperature (Tm) are not observed in a DSC (differential scanning calorimetry) analysis, or has a melting temperature (Tm) of less than 15° C, measured with a DSC instrument performing the analysis at a rate of 10° C/minute within a range of -80° C to 60° C. having an initial viscosity change ratio defined by the following relational expression 2 of 10 or more, wherein in the following relational expressions 1 and 2, V 1 is in a range of 100 Ns/m 2 (100,000 cP) to 500 Ns/m 2 (500,000 cP), V 2 is 2,000 Ns/m 2 (2,000,000 cP) or less, and V 3 satisfies 5,000 Ns/m 2 (5,000,000 cP) or more: Initial viscosity change ratio = V 2 / V 1 Initial viscosity change ratio = V 3 / V 1 wherein, V 1 is an initial viscosity, which is a viscosity value as measured at room temperature within 60 seconds after mixing main agent and curing agent components of the resin composition, V 2 is a viscosity value measured after leaving the resin composition, in which V 1 has been measured, at room temperature for 5 minutes and V 3 is a viscosity value measured after leaving the resin composition, in which V 1 has been measured, at room temperature for 60 minutes, and when V 1 and V 3 are measured in a shear rate range of 0.01 to 10.0/s using a rheological property measuring device (ARES), they are viscosity values measured at a point of 2.5/s, wherein the resin composition is a room temperature curing type resin composition and comprises a two-component urethane-based resin composition, wherein the two-component urethane-based resin composition comprises an ester-based polyol resincontaining main composition part, a polyisocyanate-containing curing agent composition part, and a filler, and the ester-based polyol resin is an amorphous polyol, in which a crystallization temperature (Tc) and a melting temperature (Tm) are not observed in a DSC (differential scanning calorimetry) analysis, or has a melting temperature (Tm) of less than 15° C, measured with a DSC instrument performing the analysis at a rate of 10° C/minute within a range of -80° C to 60° C.