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TNO Bouw (author), Larbi, J.A. (author), Visser, J.H.M. (author)Various studies have indicated that the use of some ultra-accelerated mortar bar expansion test methods for assessing the alkali-silica reactivity of concrete aggregates (particularly those using 1 M NaOH solution at 80 oC) can give rise to misleading results causing certain types of aggregates to be inappropriately accepted. This is the case if...article 2002
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- TNO Bouw (author), Larbi, J.A. (author) article 2002
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Larbi, J.A. (author), Nijland, T.G. (author), TNO Bouw (author)Metamorphic petrology is a branch of geology that deals with the study of changes in rocks due changing physio-chemical conditions. As conditions shift in or out of the thermodynamic stability field of phases, new phases may appear whereas others disappear. A basic approach is mapping of so-called isograds, which are lines separating the...conference paper 2001
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TNO Bouw (author), Nijland, T.G. (author), Larbi, J.A. (author)Concrete is a poor conductor of heat. Nevertheless, heating of concrete results in physico-chemical conditions shifting in or out the thermodynamic stability field of specific phases (minerals) in the concrete, effectuating their (dis)appearance. Metamorphic petrology is a branch of geology that deals with the study of such changes; as a basic...article 2001
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- Larbi, J.A. (author), van Hees, R.P.J. (author) conference paper 2000
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Larbi, J.A. (author), Heijnen, W.M.M. (author), Brouwer, J.P. (author), Mulder, E. (author)This paper deals with a preliminary laboratory study to assess the effectiveness of thermal treatment methods to improve the quality of recycled concrete aggregate. The samples used for the study consisted of sieved fractions of crushed concrete that were subjected to various thermal treatments at temperatures of either 650 °C or 800 °C. In each...conference paper 2000
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van Hees, R.P.J. (author), Larbi, J.A. (author)The National Monument in Amsterdam (1954-'56), built as a memorial to the fallen of World War II, was restored in 1997-'98. The main material used was travertine from Tuscany (Italy), both employed for cladding the 20-m high pylon, constituting the soul of the monument, and the relieves and free standing statues connected to it. The intemal...conference paper 2000
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Larbi, J.A. (author), Heijnen, W.M.M. (author), Brouwer, J.P. (author), Mulder, E. (author), International Cement Microscopy Association (author)In this paper, the results of a preliminary laboratory study to assess the effectiveness of thermally treating recycled concrete aggregate for genera) use in concrete are presented. The samples used for the study consisted of sieved fractions of crushed concrete that were subjected to various thermal treatments at temperatures of either 650 °C...conference paper 2000
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Larbi, J.A. (author), Visser, J.H.M. (author), TNO Bouw (author)Microscopical analysis of concrete in a deteriorating structure involves investigative techniques that make use of various analytical methods to solve specific problems related to the concrete. The technique is quick and particularly useful for diagnosing concrete deterioration and damage problems such as alkali-silica reactions, sulphate attack...conference paper 1999
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Heijnen, W.M.M. (author), Larbi, J.A. (author), TNO Bouw (author)In CUR-Recommendation 38, various vital measures that need to be taken during design of new concrete-mixtures in order to prevent damage due to ASR in the concrete have been outlined. The most important of these measures are: • the use of blast furnace slag cement (with a high slag content: 50 % by mass of cement as slag); • or the use of...conference paper 1999
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Larbi, J.A. (author), van Hees, R.P.J. (author), TNO Bouw (author)The Dutch National Monument in Amsterdam, a World War-II memorial structure, was built with an outer face consisting of slabs of travertine. In 1995, the masonry structure forming the core of the monument showed severe deterioration. In order to determine the actual cause of deterioration and to advise on the most suitable method of restoration,...conference paper 1999
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van Hees, R.P.J. (author), Larbi, J.A. (author), TNO Bouw (author)In 1997-1998 onderging het Nationaal Monument te Amsterdam een ingrijpende restauratie. Hierbij werd het monument compleet gedemonteerd, werd de gemetselde kern gesloopt en vervangen door een prefab betonnen kern en werden beelden en reliëfs conserverend behandeld. Dit artikel gaat in op de aanleiding tot en het resultaat van de conserverende...conference paper 1999
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Larbi, J.A. (author), van Hees, R.P.J. (author), TNO Bouw (author)The Dutch National Monument in Amsterdam, a World War-II memorial structure, was built with an outer face consisting of slabs of travertine. In 1995, the masonry structure forming the core of the monument showed severe deterioration. In order to determine the actual cause of deterioration and to advise on the most suitable method of restoration,...article 1999
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Brocken, H.J.P. (author), Larbi, J.A. (author), Pel, L. (author), van der Pers, N.M. (author), TNO Bouw (author)The formation of cured mortar structure in masonry was studied using multiple experimental techniques. Starting with fresh mortar, nuclear magnetic resonance (NMR) was used to measure the water extraction during brick laying. After curing, the composition of cured mortar was investigated with polarizing and fluorescent microscopy (PFM) and X-Ray...article 1999
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Larbi, J.A. (author), TNO Bouw (author)The term coating is used to denote a thin synthetic or polymer-based material that is applied to the surface of concrete in order to protect it from damage. In addition to good compatibility and bonding to substrates and adequate crack-bridging ability, coatings are designed to be durable in the environment in which they are applied. Yet, very...conference paper 1999
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TNO Bouw (author), Heijnen, W.M.M. (author), Larbi, J.A. (author)In CUR-Recommendation 38, various vital measures that need to be taken during design of new concrete-mixtures in order to prevent damage due to ASR in the concrete have been outlined. The most important of these measures are: - the use of blast furnace slag cement (with a high slag content: ≥50% by mass of cement as slag); - or the use of...article 1999
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- TNO Bouw (author), Groot, C.J.W.P. (author), Larbi, J.A. (author) article 1999
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Brocken, H.J.P. (author), Spiekman, M.E. (author), Pel, L. (author), Kopinga, K. (author), Larbi, J.A. (author), TNO Bouw (author)The water extraction out of mortar during brick laying was studied using nuclear magnetic resonance. The experiments show that using a fired-clay brick, the water is extracted out of the mortar within 3 minutes, whereas in the case of a sand-lime brick this takes about 10 minutes. Prewetting a fired-clay brick hardly affects the water extraction...article 1998
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TNO Bouw (author), Larbi, J.A. (author), Heijnen, W.M.M. (author)This article presents the results of a microscopic analysis to determine the cement content of five samples of hardened concrete prepared with portland pozzolanic cement and crushed limestone as part of the aggregate. The volume fraction of the coarse aggregate was determined macroscopically from polished plates of the concrete samples. The...article 1997
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Stoop, B.T.J. (author), Larbi, J.A. (author), Heijnen, W.M.M. (author)It is shown that it is possible to produce compacted gypsum with a low porosity and a high strength on a laboratory scale by uniaxial compaction of flue gas desulphurization (FGD-) gypsum powder. Compacted FGD-gypsum cylinders were produced at a compaction pres-sure between 50 and 500 MPa yielding porosities after compaction between 21 and 6%...article 1996