Portland cement

Abstract: 1. Portland Cement. 2. Cementitious Materials Of Different Types. 3. Properties Of Aggregate. 4. Fresh Concrete. 5. Admixtures. 6. Strength Of Concrete. 7. Further Aspects Of Hardened Concrete. 8. Temperature Effects In Concrete. 9. Elasticity, Shrinkage And Creep. 10. Durabilty Of Concrete. 11. Effects Of Freezing And Thawing And Of Chlorides. 12. Testing Of Hardened Concrete. 13. Concretes With Particular Properties. 14. Selection Of Concrete Mix Proportions (Mix Design). Appendices. Index.

Abstract: The history of calcareous cements Portland cements - classification, raw materials and processes of manufacture cement components and their phase relations the structure and cementing qualities of cement compounds the constitution of Portland cement the burning of Portland cement the hydration of Portland cement the setting and hardening of Portland cement resistance of concrete to natural destructive agencies physical and mechanical properties of Portland cement pozzolanas and pozzolanic cements cements made from blast furnace slag high alumina cement some special cements and cement properties cement admixtures concrete aggregates.

Abstract: This article discusses the practicality of replacing portland cements with alternative hydraulic cements that could result in lower total CO 2 emissions per unit volume of concrete of equivalent performance. Currently, the cement industry is responding rapidly to the perceived societal need for reduced CO 2 emissions by increasing the production of blended portland cements using supplementary cementitious materials that are principally derived from industrial by-products, such as blast-furnace slags and coal combustion fly ashes. However, the supplies of such by-products of suitable quality are limited. An alternative solution is to use natural pozzolans, although they must still be activated either by portland cement or lime or by alkali silicates or hydroxides, the production of all of which still involves significant CO 2 emissions. Moreover, concretes based on activated pozzolans often require curing at elevated temperatures, which significantly limits their field of application. The most promising alternative cementing systems for general concrete applications at ambient temperatures currently appear to be those based at least in part on calcium sulfates, the availability of which is increasing due to the widespread implementation of sulfur dioxide emission controls. These include calcium sulfoaluminate–belite–ferrite cements of the type developed in China under the generic name “Third Cement Series” (TCS) and other similar systems that make good use of the potential synergies among calcium sulfate, calcium silicate and calcium aluminate hydrates. However, a great deal more research is required to solve significant unresolved processing and reactivity questions and to establish the durability of concretes made from such cements. If we are to use these potentially more CO 2 -efficient technologies on a large enough scale to have a significant global impact, we will also have to develop the performance data needed to justify changes to construction codes and standards.

Abstract: There is a burgeoning interest in the development, characterization, and implementation of alternatives to Portland cement as a binder in concrete. The construction materials industry is under increasing pressure to reduce the energy used in production of Portland cement clinker and the associated greenhouse gas emissions. Further, Portland cement is not the ideal binder for all construction applications, as it suffers from durability problems in particularly aggressive environments. Several alternative binders have been available for almost as long as Portland cement, yet have not been extensively used, and new ones are being developed. In this paper, four promising binders available as alternatives to Portland cement are discussed, namely calcium aluminate cement, calcium sulfoaluminate cement, alkali-activated binders, and supersulfated cements. The history of the binders, their compositions and reaction mechanisms, benefits and drawbacks, unanswered questions, and primary challenges are described.