A chemical additive for calcium sulphoaluminate-modified Portland cement comprises the following substances: (a) at least one alkanolamine borate; (b) at least one organic alcohol; and (c) at least one saccharide or a derivative thereof; and the substances and water are sequentially mixed and stirred to obtain the chemical additive for calcium sulphoaluminate-modified Portland cement. The chemical additive for calcium sulphoaluminate-modified Portland cement provided by the invention has better effects of regulating the setting time of the calcium sulphoaluminate-modified Portland cement and improving the 3d/28d strength increase rate, and also has a grinding aid effect when being added during grinding.

Disclosed herein are cement compositions using set-delayed cement compositions in subterranean formations. The composition may comprise a set-delayed cement composition comprising pumice, hydrated lime, a cement set retarder, a synthetic smectite, and water.

Disclosed herein are cement compositions using set-delayed cement compositions in subterranean formations. The composition may comprise a set-delayed cement composition comprising pumice, hydrated lime, a cement set retarder, a synthetic smectite, and water.

Disclosed herein are cement compositions and methods of using set-delayed cement compositions in subterranean formations. In one embodiment a method of cementing in a subterranean formation is described. The method comprises providing a set-delayed cement composition comprising pumice, hydrated lime, a cement set retarder, a synthetic smectite, and water; introducing the set-delayed cement composition into a subterranean formation; and allowing the set-delayed cement composition to set in the subterranean formation.

Disclosed herein are cement compositions and methods of using set-delayed cement compositions in subterranean formations. In one embodiment a method of cementing in a subterranean formation is described. The method comprises providing a set-delayed cement composition comprising pumice, hydrated lime, a cement set retarder, a synthetic smectite, and water; introducing the set-delayed cement composition into a subterranean formation; and allowing the set-delayed cement composition to set in the subterranean formation.

Examples of new polymer-modified cement formulations with self-healing capability at ambient temperature are described. These polymer-modified cements can be readily mixed with typical fine and coarse aggregates to build new concrete structures. One example of such a formulation includes a concrete comprising a MBA-BDA polymer having bond forming chemical functionality configured to form a bonding matrix between the polymer and at least one component of the concrete at a temperature less than 50 degrees C. wherein the matrix obtains at least 70% recovery of compressive strength after a damage event.