Abstract: A non-dispersible concrete for underwater and underground construction is disclosed, whose composition primarily comprises: coarse aggregate in a range of from 600 to 1200 kgw/m3; fine aggregate 500 to 1100 kgw/m3, with a fineness modulus (F.M.) in a range of from 2.2 to 3.2; powder 300 to 700 kgw/m3; mixing water 140 to 300 kgw/m3; and cohesion-enhancing admixture (for example, polyacrylamide, PAA) whose solid content is 0.1 to 5.0 wt % of the powder. In addition, a SCC for underwater and underground construction is also developed and has excellent property of self-consolidation (its test value is 400 to 750 mm in slump flow spread test) and an appropriate compressive strength (between 14 to 70 MPa), so as can be widely applied to underwater and underground construction, whose composition further includes superplasticizer with solid content 0.1 to 3.0 wt % of the powder. Also, it covers: water to binder ratio (W/B) of 0.22 to 1.00, paste volume 0.25 to 0.60 m3, and water/powder volume ratio 0.5 to 2.95.

Abstract: A self-curing concrete is provided to absorb water from atmosphere from air to achieve better hydration of cement in concrete. It solves the problem that the degree of cement hydration is lowered due to no curing or improper curing, and thus unsatisfactory properties of concrete. According to the invention, high-performance self-curing agent about 0.1˜5 wt % of cement weight of the concrete is added to concrete during mixing. The self-curing agent can absorb moisture from atmosphere and then release it to concrete. The self-curing concrete means that no curing is required for concrete, or even no any external supplied water is required after placing. The properties of this self-cured concrete of this invention are at least comparable to and even better than those of concrete with traditional curing.

Abstract: A method for self-curing concrete is provided to solve the problem that the degree of cement hydration is lowered due to the improper curing, and thus unsatisfactory properties of concrete. According to the invention, at least a layer of self-curing agent is applied onto a concrete after placing. The self-curing agent can absorb moisture from atmosphere and then release it into concrete. The concrete can be self-cured without the need for applying extra water or external curing.

Abstract: A rheometer can be used to measure yield stress and viscosity of a cement-based material with excellent results. It mainly includes a drum and at least one adaptive vane assembly. The adaptive vane assembly is replaceably connected to a shaft. The shaft rotates relative to the drum. The ratio of radius (r1) of the adaptive vane assembly to radius (r0) of the drum is between 0.1˜0.6. The shaft is rotated with a minimum rotational speed more than 0.001 rad/s, and then can measure its torque at constant speed. Accordingly, the rheometer can greatly reduce the disturbance of vanes of the adaptive vane assembly upon the cement-based materials and reduce the slippage among particles and the vanes. Moreover, the minimum shear stress is defined as a yield stress.

Abstract: A non-dispersible concrete for underwater and underground construction is disclosed, whose composition primarily comprises: coarse aggregate in a range of from 600 to 1200 kgw/m3; fine aggregate 500 to 1100 kgw/m3, with a fineness modulus (F.M.) in a range of from 2.2 to 3.2; powder 300 to 700 kgw/m3; mixing water 140 to 300 kgw/m3; and cohesion-enhancing admixture (for example, polyacrylamide, PAA) whose solid content is 0.1 to 5.0 wt % of the powder. In addition, a SCC for underwater and underground construction is also developed and has excellent property of self-consolidation (its test value is 400 to 750 mm in slump flow spread test) and an appropriate compressive strength (between 14 to 70 MPa), so as can be widely applied to underwater and underground construction, whose composition further includes superplasticizer with solid content 0.1 to 3.0 wt % of the powder. Also, it covers: water to binder ratio (W/B) of 0.22 to 1.00, paste volume 0.25 to 0.60 m3, and water/powder volume ratio 0.5 to 2.95.

Abstract: A self-curing concrete is provided to absorb water from atmosphere from air to achieve better hydration of cement in concrete. It solves the problem that the degree of cement hydration is lowered due to no curing or improper curing, and thus unsatisfactory properties of concrete. According to the invention, high-performance self-curing agent about 0.1˜5 wt % of cement weight of the concrete is added to concrete during mixing. The self-curing agent can absorb moisture from atmosphere and then release it to concrete. The self-curing concrete means that no curing is required for concrete, or even no any external supplied water is required after placing. The properties of this self-cured concrete of this invention are at least comparable to and even better than those of concrete with traditional curing.

Abstract: A rheometer can be used to measure yield stress and viscosity of a cement-based material with excellent results. It mainly includes a drum and at least one adaptive vane assembly. The adaptive vane assembly is replaceably connected to a shaft. The shaft rotates relative to the drum. The ratio of radius (r1) of the adaptive vane assembly to radius (r0) of the drum is between 0.1˜0.6. The shaft is rotated with a minimum rotational speed more than 0.001 rad/s, and then can measure its torque at constant speed. Accordingly, the rheometer can greatly reduce the disturbance of vanes of the adaptive vane assembly upon the cement-based materials and reduce the slippage among particles and the vanes. Moreover, the minimum shear stress is defined as a yield stress.