Cement paste composition
A cement paste composition includes a curable component including a cementitious material and a zeolitic imidazolate framework-67 (ZIF-67) present in an amount of 0.01 to 3% by weight based on a total weight of the cementitious material. The composition further includes water in an amount of 30 to 50% by weight based on a total weight of the cement paste composition. A cured specimen made from the cement paste composition has a compressive strength of 30 to 80 megapascal (MPa) according to ASTM C109/C109M-21 standard test method, and a direct tensile strength of 1.2 to 2.2 MPa according to ASTM C307-18 standard test method. The ZIF-67 particles are uniformly distributed throughout the cured specimen. A method of producing the cement paste specimen.
1 . A cement paste composition, comprising:
a curable component comprising a cementitious material and a zeolitic imidazolate framework-67 (ZIF-67) present in an amount of 0.01 to 3% by weight based on a total weight of the cementitious material;
water in an amount of 30 to 50% by weight based on a total weight of the cement paste composition;
wherein a cured specimen made from the cement paste composition has a compressive strength of 30 to 80 megapascal (MPa) according to ASTM C109/C109M-21 standard test method, and a direct tensile strength of 1.2 to 2.2 MPa according to ASTM C307-18 standard test method, and wherein the ZIF-67 particles are uniformly distributed throughout the cured specimen,
wherein the compressive strength of the cured specimen made from the cement paste composition is 40 to 50% greater than that of a cured specimen made from a cement paste composition without the ZIF-67 as determined by ASTM C109/C109M-21.
2 . The cement paste composition of claim 1 , wherein the cementitious material comprises at least one selected from the group consisting of portland cement, pozzolan cement, gypsum cement, aluminous cement, silica cement, and alkaline cement.
3 . The cement paste composition of claim 1 , wherein the cementitious material is type I ordinary portland cement (OPC), and wherein the OPC has a standard specification of ASTM C150-21.
4 . The cement paste composition of claim 1 , wherein the ZIF-67 is present in the curable component of the cement paste composition in an amount of 0.1 to 1% by weight based on the total weight of the cementitious material.
5 . The cement paste composition of claim 1 , wherein the ZIF-67 particles have a mean particle size in a range of 5 to 150 nanometers (nm).
6 . The cement paste composition of claim 1 , wherein the ZIF-67 particles have a porous structure, and a mean pore size in a range of 0.5 to 5 nm.
7 . The cement paste composition of claim 1 , wherein the water is at least one selected from the group consisting of tap water, ground water, distilled water, deionized water, fresh water, and desalted water.
8 . The cement paste composition of claim 1 , wherein the water is desalted water, and wherein the desalted water is present in the cement paste composition in an amount of 35 to 45% by weight based on the total weight of the cement paste composition.
9 . The cement paste composition of claim 1 , wherein the direct tensile strength of the cured specimen made from the cement paste composition is 100 to 120% greater than that of a cured specimen made from a cement paste composition without the presence of ZIF-67 as determined by ASTM C307-18.
10 . A cement specimen comprising a cement paste composition a cured form,
wherein the cement paste composition comprises:
a curable component comprising a cementitious material and a zeolitic imidazolate framework-67 (ZIF-67) present in an amount of 0.01 to 3% by weight based on a total weight of the cementitious material;
water in an amount of 30 to 50% by weight based on a total weight of the cement paste composition;
wherein the cured specimen has a compressive strength of 30 to 80 megapascal (MPa) according to ASTM C109/C109M-21 standard test method, and a direct tensile strength of 1.2 to 2.2 MPa according to ASTM C307-18 standard test method,
wherein the ZIF-67 particles are uniformly distributed throughout the cured specimen, and
wherein a weight ratio of the water to the curable component is in a range of 0.3:1 to 0.5:1,
wherein the cured specimen has a plurality of calcium silicate hydrates, wherein the calcium silicate hydrate has a layered structure with a basal spacing of 5 to 20 angstroms (Å) and a sheet morphology.
11 . The cement specimen of claim 10 , having a water absorption of 15 to 25% by weight based on a total weight of the cement paste composition after curing.
12 . The cement specimen of claim 10 , having a dry density of 1.55 to 1.80 g/cm 3 after curing.
13 . The cement specimen of claim 10 , having a higher degree of hydration than that of a cement paste made from the same composition but without the ZIF-67 according to ASTM C1679-17 standard test method.