The issue of concrete strength often arises in civil engineering practice, either due to quality control of new constructions or due to the assessment of existing structures. In spite of the large amount of research work performed in the last decades, the uncertainties of the rebound test are still not clearly quantified and open to further insight. This paper presents and discusses a wide research campaign on laboratory specimens and on third-party specimens delivered to the Laboratory for Building Materials of the University of Genoa, Italy, for standard quality controls. While it is well known that moisture content, surface finishing, and concrete maturity strongly affect the test result, the effect of the stress state has not yet been studied and is found in this research to be a further parameter affecting the test reliability. As already demonstrated by many authors, the results of this research also show that a universal calibration curve to be used for any concrete, in any condition, conceptually does not exist.
From a coastal library by MAD to an adaptive reuse project by Tadao Ando , we've rounded up 12 of the most interesting architecture projects that are slated for completion in It will have a sinuous, white-concrete form punctured by large circular cut-outs, intended to evoke "a wormhole that transcends time and space". In Niger, Adjaye Associates will complete a memorial to the people who lost their lives fighting terrorists on the borders of the West African country. It will be distinguished by a grid of 56 star-shaped concrete columns that extend 20 metres into the air and are raised on a large room for civic events. As part of the project, the studio has replaced some of the building's 19th-century facades with a new transparent skin, which it describes as "a set of etched glass waves". It was originally expected to open in , but construction has halted several times due to various court cases and campaigns opposing the alterations. Formerly known as Pier 55, the project consists of mushroom-shaped columns that will support an undulating green landscape.
Brandon K. Bailey , University of Denver Follow. Rock glaciers are common landform features found in deglaciated alpine areas. They are commonly used in the study of climatic changes throughout the Holocene and the reconstruction of neoglacial chronologies.
This paper presents new data and discussion to clarify and to evaluate calibration procedures. These make a distinction between Schmidt Hammer drift following use instrument calibration , and variation between both individual Schmidt Hammers and between user strategies when utilising age-calibration curves age calibration. A range of surfaces were tested using 3 N-Type Schmidt Hammers, which showed that existing anvil calibration procedures led to consistent overestimation of R-values by up to In contrast, new calibration procedures, which are based on the use of a calibration point which lies within the range of R-values measured in the field [Dortch et al. Moreover, these new calibration procedures are more appropriate for age calibration as they incorporate operator variance through choice of sampling location.