| Titre : | The mechanical and physical properties of epoxy resins and their influence on the performance of screeds | | Type de document : | texte imprimé | | Auteurs : | O. Bendeddouche, Auteur ; D. R. Plum, Directeur de thèse | | Editeur : | University of Newcastle Upon Tyne | | Année de publication : | 1985 | | Importance : | 152 f. | | Présentation : | ill. | | Format : | 30 cm. | | Note générale : | Mémoire de Master : Génie Civil : Angleterre, University of Newcastle Upon Tyne : 1985
Bibliogr. [5] f. Annexe [15] f | | Langues : | Anglais (eng) | | Mots-clés : | Epoxy resin mortars
Shrinkage
Linear thermal expansion
Flexural strength
Correlation | | Index. décimale : | Ms00985 | | Résumé : | The physical and mechanical properties of five Epoxy resin mortars, having different formulations, have been investigated.
The ultimate shrinkage is found to compare with that of P.C. concrete.
It ranges between 0.03 and 0.06%.
However, the rate of development of shrinkage is much higher than of P.C. concrete.
The coefficient of linear thermal expansion is 3 to 5 times that of P.C. contrete.
It ranges between 32 x 10⁻⁶ °/C within a temperature range of 20 to 40°C.
However, it does not remain constant beyond 40°C.
At room temperature, the rate of development of the flexural strength is significantly higher than that of P.C. concrete.
The ultimate value is about 4 to 6 times that of a high-strength P.C. concrete.
The modulus of elasticity in tension is generally lower than the one in flexure which is of the order of that P.C. concrete.
Poisson's ratio ranges between 0.16 and 0.30.
Most of the values are higher than 0.2 which is higher than that of P.C. concrete.
The development of the flexural modulus of elasticity at three different curing temperatures has been examined.
It is higher than that of P.C. concrete.
It has been observed that, in general, the higher the curing temperature the higher the ultimate value.
This is in the range of about 18 ̴ 25 KN/mm² (at 20°C), 22 ̴ 29 KN/mm² (at 50°C) and 23 ̴ 31 KN/mm² (at 70°C).
The correlation between curing temperature and rate of development of the flexural modulus of elasticity was not general.
The effect of post-curing on the flexural modulus of elasticity, after this had stabilized, has been investigated.
Post-curing at higher temperatures for 24 hours has not been found to have the same effect as curing entirely at the same temperature.
Generally, the flexural modulus of elasticity increased up to a certain post-curing temperature after which it decreased.
This has been attributed to a partial loss of bond between matrix and aggregate.
The effect of applied stress and that of age at first loading on creep in flexure has been examined on one of the E.R. mortars (Screed.G).
The creep increases with the increase of stress level ranging between 1/3 and 2/3.
The effect of age at first loading was noticeable only between 1 and 5 days.
At any applied stress and any age at first loading investigated, the creep showed primary, secondary and tertiary stage followed by failure of the specimens.
No general correlation has been observed between the creep coeffocoent and stress level.
Various cases of failure have been reported, where E.R. mortars screeds were applied on inadequately prepared P.C. concrete surfaces.
Due to the weak or inexistent bond between the topping and the substrate, any excess in linear expansion would cause instability failure of the topping.
Also, the case, where the substrate surface has been adequately prepared but possess geometrical imperfections, has been considered.
From a theoretical approach, the critical value of the linear expansion strain, likely to cause failure, is derived. |
The mechanical and physical properties of epoxy resins and their influence on the performance of screeds [texte imprimé] / O. Bendeddouche, Auteur ; D. R. Plum, Directeur de thèse . - [S.l.] : University of Newcastle Upon Tyne, 1985 . - 152 f. : ill. ; 30 cm. Mémoire de Master : Génie Civil : Angleterre, University of Newcastle Upon Tyne : 1985
Bibliogr. [5] f. Annexe [15] f Langues : Anglais ( eng) | Mots-clés : | Epoxy resin mortars
Shrinkage
Linear thermal expansion
Flexural strength
Correlation | | Index. décimale : | Ms00985 | | Résumé : | The physical and mechanical properties of five Epoxy resin mortars, having different formulations, have been investigated.
The ultimate shrinkage is found to compare with that of P.C. concrete.
It ranges between 0.03 and 0.06%.
However, the rate of development of shrinkage is much higher than of P.C. concrete.
The coefficient of linear thermal expansion is 3 to 5 times that of P.C. contrete.
It ranges between 32 x 10⁻⁶ °/C within a temperature range of 20 to 40°C.
However, it does not remain constant beyond 40°C.
At room temperature, the rate of development of the flexural strength is significantly higher than that of P.C. concrete.
The ultimate value is about 4 to 6 times that of a high-strength P.C. concrete.
The modulus of elasticity in tension is generally lower than the one in flexure which is of the order of that P.C. concrete.
Poisson's ratio ranges between 0.16 and 0.30.
Most of the values are higher than 0.2 which is higher than that of P.C. concrete.
The development of the flexural modulus of elasticity at three different curing temperatures has been examined.
It is higher than that of P.C. concrete.
It has been observed that, in general, the higher the curing temperature the higher the ultimate value.
This is in the range of about 18 ̴ 25 KN/mm² (at 20°C), 22 ̴ 29 KN/mm² (at 50°C) and 23 ̴ 31 KN/mm² (at 70°C).
The correlation between curing temperature and rate of development of the flexural modulus of elasticity was not general.
The effect of post-curing on the flexural modulus of elasticity, after this had stabilized, has been investigated.
Post-curing at higher temperatures for 24 hours has not been found to have the same effect as curing entirely at the same temperature.
Generally, the flexural modulus of elasticity increased up to a certain post-curing temperature after which it decreased.
This has been attributed to a partial loss of bond between matrix and aggregate.
The effect of applied stress and that of age at first loading on creep in flexure has been examined on one of the E.R. mortars (Screed.G).
The creep increases with the increase of stress level ranging between 1/3 and 2/3.
The effect of age at first loading was noticeable only between 1 and 5 days.
At any applied stress and any age at first loading investigated, the creep showed primary, secondary and tertiary stage followed by failure of the specimens.
No general correlation has been observed between the creep coeffocoent and stress level.
Various cases of failure have been reported, where E.R. mortars screeds were applied on inadequately prepared P.C. concrete surfaces.
Due to the weak or inexistent bond between the topping and the substrate, any excess in linear expansion would cause instability failure of the topping.
Also, the case, where the substrate surface has been adequately prepared but possess geometrical imperfections, has been considered.
From a theoretical approach, the critical value of the linear expansion strain, likely to cause failure, is derived. |
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