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Capturing the long-term performance of concrete must be underpinned by a detailed understanding of the pore structure. Mercury intrusion porosimetry (MIP) is a widely used technique for pore structure characterization. However, it has been proven inappropriate to measure the pore size distribution of cementitious materials due to the ink-bottle effect. MIP with cyclic pressurization-depressurization can overcome the ink-bottle effect and enables a distinction between large (ink-bottle) pores and small (throat) pores. In this paper, pressurization-depressurization cycling mercury intrusion porosimetry (PDC-MIP) is adopted to characterize the pore structure in a range of cementitious pastes cured from 28 to 370 days. The results indicate that PDC-MIP provides a more accurate estimation of the pore size distribution in cementitious pastes than the standard MIP. Bimodal pore size distributions can be obtained by performing PDC-MIP measurements on cementitious pastes, regardless of the age. Water-binder ratio, fly ash and limestone powder have considerable influences on the formation of capillary pores ranging from 0.01 to 0.5 μm., Materials and Environment

In this study, non-destructive methods are applied to quantify the influence of concrete degradation by geologic conditions on the ability to retain nuclear waste deep underground in The Netherlands. Nuclear reactors play an important role in all four scenarios of the recent report of the IPCC to reach the CO2 reduction goals. Safety related criticism against nuclear energy technology are less relevant for Generation IV nuclear power plants, of which several are scheduled to be constructed in Europe within the next few years. This is partially due to the inherent safety features of Gen IV power plant designs, where disasters experienced before (e.g., Chernobyl, Fukushima) are technically impossible. Concrete samples provided by COVRA are degraded by immersion in a solution that contains chlorides and sulphates in concentration levels that are similar to geologic conditions. The influence of concrete degradation on the internal structure of concrete has been investigated using X-ray and Neutron radiography. Pore size distributions, pore geometry and sorptivity are presented. In order to validate the results, standardized tests are performed and the results are compared., CEBAMA Project, Materials Science and Engineering

In this study, non-destructive methods are applied to quantify the influence of concrete degradation by geologic conditions on the ability to retain nuclear waste deep underground in The Netherlands. Nuclear reactors play an important role in all four scenarios of the recent report of the IPCC to reach the CO2 reduction goals. Safety related criticism against nuclear energy technology are less relevant for Generation IV nuclear power plants, of which several are scheduled to be constructed in Europe within the next few years. This is partially due to the inherent safety features of Gen IV power plant designs, where disasters experienced before (e.g., Chernobyl, Fukushima) are technically impossible. Concrete samples provided by COVRA are degraded by immersion in a solution that contains chlorides and sulphates in concentration levels that are similar to geologic conditions. The influence of concrete degradation on the internal structure of concrete has been investigated using X-ray and Neutron radiography. Pore size distributions, pore geometry and sorptivity are presented. In order to validate the results, standardized tests are performed and the results are compared., CEBAMA Project, Materials Science and Engineering

The use of cementitious materials for construction of buildings and structures started during ancient civilization. Science of modifying physical and chemical properties of cementitious materials is a continual process which is because of a need to increase reactivity and improve strength and durability properties of binders. Due to increasing demand of modern infrastructures and continual depleting of binder sources the scientist, engineers and researchers work hard on improving binding properties of cementitious materials for construction of low cost and durable structures. Among of the factors which affect binding properties of cementitious properties are densities, surface areas and particle size distribution. Several methods and procedures have been developed to determine these physical properties on which other require huge capital investment and others takes long time to complete a test which hinders further investigation and improvement of alternative binders.This study investigated that there exist an ‘S’ curve similar to particle size distribution curve when time air flow against weights of sample measured using Blaine apparatus is drawn. The gradients of lower and middle lines of the curve and values at turning points were synthesized to determine specific densities, specific surface areas and particle size distribution of powder materials. The approach is time saving and the equipment is affordable by many researchers. In order to have accurate results the approach can be automated.

The use of cementitious materials for construction of buildings and structures started during ancient civilization. Science of modifying physical and chemical properties of cementitious materials is a continual process which is because of a need to increase reactivity and improve strength and durability properties of binders. Due to increasing demand of modern infrastructures and continual depleting of binder sources the scientist, engineers and researchers work hard on improving binding properties of cementitious materials for construction of low cost and durable structures. Among of the factors which affect binding properties of cementitious properties are densities, surface areas and particle size distribution. Several methods and procedures have been developed to determine these physical properties on which other require huge capital investment and others takes long time to complete a test which hinders further investigation and improvement of alternative binders.This study investigated that there exist an ‘S’ curve similar to particle size distribution curve when time air flow against weights of sample measured using Blaine apparatus is drawn. The gradients of lower and middle lines of the curve and values at turning points were synthesized to determine specific densities, specific surface areas and particle size distribution of powder materials. The approach is time saving and the equipment is affordable by many researchers. In order to have accurate results the approach can be automated.

The use of cementitious materials for construction of buildings and structures started during ancient civilization. Science of modifying physical and chemical properties of cementitious materials is a continual process which is because of a need to increase reactivity and improve strength and durability properties of binders. Due to increasing demand of modern infrastructures and continual depleting of binder sources the scientist, engineers and researchers work hard on improving binding properties of cementitious materials for construction of low cost and durable structures. Among of the factors which affect binding properties of cementitious properties are densities, surface areas and particle size distribution. Several methods and procedures have been developed to determine these physical properties on which other require huge capital investment and others takes long time to complete a test which hinders further investigation and improvement of alternative binders.This study investigated that there exist an ‘S’ curve similar to particle size distribution curve when time air flow against weights of sample measured using Blaine apparatus is drawn. The gradients of lower and middle lines of the curve and values at turning points were synthesized to determine specific densities, specific surface areas and particle size distribution of powder materials. The approach is time saving and the equipment is affordable by many researchers. In order to have accurate results the approach can be automated.

In this study the cracking and debonding behaviour of cementitious screeds bonded to concrete bearing floors is analysed. In order to obtain insight in this behaviour research is performed to the surface tensile strength of concrete, the bond strength of screeds on concrete bearing floors, the behaviour of screeds during shrinkage and the methods to determine the bond strength. This research is carried out by a theoretical study in which the screed shrinkage behaviour as well as the screed / concrete behaviour during testing of the bond strength is analysed by means of analytical and FEM studies. Besides this practical experiments are performed to obtain insight in the influence of different parameters on the surface tensile strength of concrete / the bond strength of screeds on concrete bearing floors. Furthermore practical experiments are executed to study the influence of different parameters on the outcome of a preferred bond strength testing method.

In this study the cracking and debonding behaviour of cementitious screeds bonded to concrete bearing floors is analysed. In order to obtain insight in this behaviour research is performed to the surface tensile strength of concrete, the bond strength of screeds on concrete bearing floors, the behaviour of screeds during shrinkage and the methods to determine the bond strength. This research is carried out by a theoretical study in which the screed shrinkage behaviour as well as the screed / concrete behaviour during testing of the bond strength is analysed by means of analytical and FEM studies. Besides this practical experiments are performed to obtain insight in the influence of different parameters on the surface tensile strength of concrete / the bond strength of screeds on concrete bearing floors. Furthermore practical experiments are executed to study the influence of different parameters on the outcome of a preferred bond strength testing method.

Borehole sealing is required for different purposes, like permanent tightening of deep holesbored in conjunction with site investigations for location of radioactive waste repositories, andtemporary plugging of holes carrying water in deep mines. The holes will pass through low-permeablerock as well as through water-bearing fracture zones. Sealing can preferably bemade by use of concrete where such zones are intersected, while very low-permeable clayseals can be placed where the holes are surrounded by tight rock. This study focuses on withconcrete seals, and on grouts used for stabilizing intersected fracture zones before boreholesealing is started.The work on concrete comprised comparison of two recipes with different superplasticizers,i.e. organic Glenium which is currently used on a large scale, and talc being an inorganic,hydrophobic material. The study included determination of the compressive and tensilestrength as functions of time, and fluidity, pH and hydraulic conductivity of matured concrete.Part of the study concerned grouts for sealing of rock fractures. Two cement brands were usedas for the concrete study. The effect of adding palygorskite and talc to the silicious aggregatematerial for enhancing fluidity was tested. The work included determination of properties likestrength and fluidity., Validerat; 20120614 (anonymous)

The objectives of the study were to: (a) Develop a plan which would contribute to ensuring reproducibility of diagnostic methods used in research and development on repository sealing materials; (b) Compare results of tests performed by similar methods on similar cementitious seal materials, conducted and prepared in each of the two laboratories; (c) Use the results of complementary, but not identical, tests performed in the two laboratories to cofirm the validity of performance-related information gained; and (d) Generate data on a plugging material which could be a candidate for repository sealing in halite or anhydrite host formations or formations containing both halite and anhydrite., Prepared in cooperation with Pennsylvania State Univ., University Park. Materials Research Lab. Supersedes Rept. no. ONWI-198, WES/MP/SL-81-2, AD-A097 456.

Surface deterioration of exposed transportation structures is a major problem. In most cases, surface deterioration could lead to structural problems because of the loss of cover and ensuing, reinforcement corrosion. To minimize the deterioration, various types of coatings have been tried over, three decades with different degrees of success. For successful long-term performance, the coating, material itself should be durable, should bond well to the patent surface, and be compatible with, parent surface in terms of expansion or contraction during temperature changes.