First noticed by T. C. Powers, et al in 1948, [22] as beneficial for hydration by supplying water internally, specifiers and contractors in 2012 have grasped how the process of internal curing is implemented, how hydration behaves, and how improvements in mechanical properties, durability, and cost may be beneficial. To meet the time-dependent hydration needs of the concrete, having sufficient water internally available, when, as, and where needed, is vital for achieving optimum characteristic qualities. There is lower life cycle cost with internal curing (IC) and frequently lower first cost. In 2012, the number of projects using internal curing is increasing at an escalating rate, because the process is simple and economically implemented. Pavements, bridges, buildings, and pervious parking lots are being started now in this recession, because specifiers and contractors are saving dollars, as they build longer lasting structures while costs and interest rates are low. Developed initially to reduce autogenous shrinkage in low water-cement ratio and high performance concretes, internal curing has been found to reduce drying shrinkage. Other benefits found include reduced permeability, increased compressive and flexural strengths, less warping, stronger interfacial transition zones, greater durability, and lower carbonation.

Portland Cement Pervious Concrete (PCPC) is a material of increasing interest for parking lots and other applications. PCPC typically consists of coarse aggregates, portland cement, water, and various admixtures. In this research, in-service PCPC pavements were inspected in the field, and cores were removed in order to investigate properties in the laboratory. Field evaluation methods included visual inspection, two surface drainage measurements, and indirect transmission ultrasonic pulse velocity (UPV). Laboratory testing methods included void ratio, unit weight, compressive strength, splitting tensile strength, hydraulic conductivity, and direct transmission UPV. Because it is compacted on the surface with screeds or rollers, PCPC generally has higher strength, lower void ratio, and lower hydraulic conductivity at the surface than at the bottom. Therefore, the properties of the tops and bottoms of core samples were compared. Generally, the PCPC installations evaluated under this research project have performed well in freeze-thaw environments with little maintenance required. No visual indicators of freeze-thaw damage were observed. With the exception of some installations where the pore structure was sealed during construction with wet mixtures or over compaction, nearly all sites showed fair to good infiltration capability based on drain time measurements.

Temperature effects are the predominant cause for volume change in concrete pavements. This paper describes an experimental investigation of thermal volume change conducted to improve the understanding of joint movement in concrete pavement. Four slab strips containing embedded strain gauges and thermocouples were monitored in a controlled environment under four heating rates. Each strip was monitored for translation, rotation, and warping height. Key findings of the experiment include the internal strain distribution and non-linear thermal gradients produced by asymmetrical heating. The laboratory data are compared with long-term data from an instrumented parking lot pavement. Analysis of the data provides insight into the prediction of thermal movements and determination of thermal stress development in pavements.

Diagonal Mar Centro Comercial is a 350,000 square meter (3.75 million square foot) mixed use commercial development in Barcelona, Spain. It is located at the terminus of the premier boulevard in Barcelona, avenida Diagonal and will be known as Diagonal Mar - the avenue by the sea. The project is located only two hundred meters from the shores of the Mediterranean Sea and approximately ten kilometers east of the Olympic Village - home to the athletes in the 1992 Olympic Games. A commercial venture of Diagonal Mar S.A., the first phase consists of a 165,000 square meter (1.75 million square feet) retail mall and hypermarket (the largest in Spain) and six levels of underground parking for 5,100 automobiles in 185,000 square meters (2.0 million square feet) of space. Construction cost for Phase I is estimated to be $180,000,000 US dollars. Residential housing and office buildings are planned for later phases of the project. The site is a very large triangular plot bounded by the extension of avenida Diagonal on the northwest, avenida Josep Pla on the west and avenida Taulat on the south. The sides of the triangle are approximately 333 meters (1,072 feet) along avenida Diagonal, 285 meters (935 feet) along avenida Taulat and 236 meters (774 feet) along avenida Joseph Pla. The 24 meter (79 feet) deep excavation required for the underground parking, located 18 meters (59 feet) below the shallow water table, will create the largest basement substructure in the world and will remove more than 1 .O million cubic meters (1 .3 million cubic yards). The sheer size of the project and its location so close to the sea posed a whole host of enormous engineering challenges for the design and construction planning team as follows: (1) Excavation retention method; (2) Foundation system selection and design; (3) Excavation/substructure construction method and sequence, (4) Substructure system selection and design.

Reports on a field survey of over 100 projects including parking structures, slabs on ground, and miscellaneous installations that used shrinkage-compensating cement concrete. Fifty nine of the projects were rated on the effectiveness in reducing drying shrinkage cracks and it was concluded that, on average, the cement was very effective. Six years later seventeen of them were re-examined and it was found that the cement was still very effective. Cracks are plotted on several plan drawings. A number of the projects were inspected several times within a year to determine the rate and extent of cracking. Some causes of cracking due to drying shrinkage are discussed. Twelve projects of portland cement concrete were also reported.