Curing is one of those activities that every civil engineer and construction worker has heard of, but in reality does not worry about much. In practice, curing is often low on the list of priorities on the construction site, particularly when budgets and timelines are under pressure. Yet the increasing demands being placed on concrete mixtures also

The American Concrete Institute in 2010 defined internal curing as supplying water throughout a freshly placed cementitious mixture using reservoirs, via pre-wetted lightweight aggregates, that readily release water as needed for hydration or to replace moisture lost through evaporation or self-desiccation (American Concrete Institute, 2010). While internal curing has been inadvertently included in many lightweight concretes produced within the past 100 years, it is only within the first decade of the 21st century that this technology has been intentionally incorporated into concrete mixtures at the proportioning stage, using a variety of materials including pre-wetted lightweight aggregates, pre-wetted crushed returned concrete fines, superabsorbent polymers, and pre-wetted wood fibers. This report provides a state-of-the-art review of the subject of internal curing, first addressing its history and theory, andthen proceeding to summarize published guidance on implementing internal curing in practice and published research on its influence on the performance properties of concrete. The ongoing exploration of extensions of the internal curing concept that employ the internal reservoirs to contain materials other than water are reviewed. Finally, the critical issue of sustainability is addressed. An extensive internal curing bibliography that is also available over the Internet is included in an appendix. The report is mainly focused on the utilization of prewettedlightweight aggregates as the internal reservoirs due to thisbeing the current established practice within the U.S.

Durability and service life design of concrete constructions have considerable socio-economic and environmental consequences, in which the permeability of concrete to aggressive intruders plays a vital role. Concrete Permeability and Durability Performance provides deep insight into the permeability of concrete, moving from theory to practice, and presents over 20 real cases, such as Tokyo’s Museum of Western Art, Port of Miami Tunnel and Hong Kong-Zhuhai-Macao sea-link, including field tests in the Antarctic and Atacama Desert. It stresses the importance of site testing for a realistic durability assessment and details the "Torrent Method" for non-destructive measurement of air-permeability. It also delivers answers for some vexing questions: Should the coefficient of permeability be expressed in m2 or m/s? How to get a "mean" pore radius of concrete from gas-permeability tests? Why should permeability preferably be measured on site? How can service life of reinforced concrete structures be predicted by site testing of gas-permeability and cover thickness? Practitioners will find stimulating examples on how to predict the coming service life of new structures and the remaining life of existing structures, based on site testing of air-permeability and cover thickness. Researchers will value theoretical principles, testing methods, as well as how test results reflect the influence of concrete mix composition and processing.

This is the state-of-the-art report prepared by the RILEM TC “Application of Super Absorbent Polymers (SAP) in concrete construction”. It gives a comprehensive overview of the properties of SAP, specific water absorption and desorption behaviour of SAP in fresh and hardening concrete, effects of the SAP addition on rheological properties of fresh concrete, changes of cement paste microstructure and mechanical properties of concrete. Furthermore, the key advantages of using SAP are described in detail: the ability of this material to act as an internal curing agent to mitigate autogenous shrinkage of high-performance concrete, the possibility to use SAP as an alternative to air-entrainment agents in order to increase the frost resistance of concrete, and finally, the benefit of steering the rheology of fresh cement-based materials. The final chapter describes the first existing and numerous prospective applications for this new concrete additive.

Concrete made using mineral cements, the raw materials which on earth are practically endless, is known as one of the oldest building materials and during the last decades of the twentieth century has become a dominant building material for general use. At the same time, the requirements of the quality of concrete and its performance properties, in particular compressive strength, durability, economical efficiency, and low negative impact of its manufacture on the environment have not yet been completely met. Bearing these requirements in mind, researchers and engineers worldwide are working on how to satisfy these requirements. This book has been written by researchers and experts in the field and provides the state of the art on recent progress achieved on the properties of concrete, including concrete in which industrial by-products are utilized. The book is dedicated to graduate students, researchers, and practicing engineers in related fields.

The purpose of this manual is to provide clear and helpful information for maintaining gravel roads. Very little technical help is available to small agencies that are responsible for managing these roads. Gravel road maintenance has traditionally been "more of an art than a science" and very few formal standards exist. This manual contains guidelines to help answer the questions that arise concerning gravel road maintenance such as: What is enough surface crown? What is too much? What causes corrugation? The information is as nontechnical as possible without sacrificing clear guidelines and instructions on how to do the job right.