Documents disponibles écrits par cet auteur

Lumber-boxed concrete structural system—concept and preliminary analysis / Madhu M. Karthik in Journal of structural engineering, Vol. 137 N° 11 (Novembre 2011) 

Public ISBD [article]  in Journal of structural engineering > Vol. 137 N° 11 (Novembre 2011) . - pp. 1381-1389 Titre : Lumber-boxed concrete structural system—concept and preliminary analysis Type de document : texte imprimé Auteurs : Madhu M. Karthik, Auteur ; Mander, John B., Auteur ; David V. Rosowsky, Auteur Année de publication : 2012 Article en page(s) : pp. 1381-1389 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Timber  Concrete  Stress  strain  Stress  blocks  Moment  curvature Résumé : Lumber has the advantages of being a lightweight construction material, easy to handle, and environmentally benign. However, large creep deflections and significant issues with sound transmission, particularly the footfall problem, generally limit lumber use to small spans and low-rise buildings. A concrete topping on lumber subfloors may mitigate some of these issues, but even with well-engineered wood systems, the spans are relatively short. In this study, a new structural system is analytically explored. Called a lumber-boxed concrete structural system, the dual system utilizes the positive attributes of both dimensional lumber and reinforced concrete; composite action is not a requirement of the system. A stress-block approach is developed to calculate strength and deformation behavior. An analytical stress-block-based moment-curvature analysis is performed on the lumber-boxed concrete structural elements. Results show that the structural lumber-boxed concrete members may have better strength and ductility capacities when compared to an equivalent size ordinary reinforced concrete member. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i11/p1381_s1?isAuthorized=no [article] Lumber-boxed concrete structural system—concept and preliminary analysis [texte imprimé] / Madhu M. Karthik, Auteur ; Mander, John B., Auteur ; David V. Rosowsky, Auteur . - 2012 . - pp. 1381-1389. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 137 N° 11 (Novembre 2011) . - pp. 1381-1389 Mots-clés : Timber  Concrete  Stress  strain  Stress  blocks  Moment  curvature Résumé : Lumber has the advantages of being a lightweight construction material, easy to handle, and environmentally benign. However, large creep deflections and significant issues with sound transmission, particularly the footfall problem, generally limit lumber use to small spans and low-rise buildings. A concrete topping on lumber subfloors may mitigate some of these issues, but even with well-engineered wood systems, the spans are relatively short. In this study, a new structural system is analytically explored. Called a lumber-boxed concrete structural system, the dual system utilizes the positive attributes of both dimensional lumber and reinforced concrete; composite action is not a requirement of the system. A stress-block approach is developed to calculate strength and deformation behavior. An analytical stress-block-based moment-curvature analysis is performed on the lumber-boxed concrete structural elements. Results show that the structural lumber-boxed concrete members may have better strength and ductility capacities when compared to an equivalent size ordinary reinforced concrete member. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i11/p1381_s1?isAuthorized=no

Stress-block parameters for unconfined and confined concrete based on a unified stress-strain model / Madhu M. Karthik in Journal of structural engineering, Vol. 137 N° 2 (Fevrier 2011) 

Public ISBD [article]  in Journal of structural engineering > Vol. 137 N° 2 (Fevrier 2011) . - pp. 270-273 Titre : Stress-block parameters for unconfined and confined concrete based on a unified stress-strain model Type de document : texte imprimé Auteurs : Madhu M. Karthik, Auteur ; Mander, John B., Auteur Année de publication : 2011 Article en page(s) : pp. 270-273 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Concrete  Stress  strain  Stress  blocks  Confined  concrete  Moment  curvature Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Equations to obtain equivalent rectangular stress-block parameters for unconfined and confined concrete are derived for rapid (hand) analysis and design purposes. To overcome a shortcoming of existing commonly used stress-strain models that are not easy to integrate, a new stress-strain model is proposed and validated for a wide range of concrete strengths and confining stresses. The efficacy of the equivalent rectangular stress-block parameters is demonstrated for hand calculations in predicting key moment-curvature results for a confined concrete column. Results are compared with those obtained from a computational fiber-element analysis using the proposed stress-strain model and another widely used existing model; good agreement between the two is observed. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i2/p270_s1?isAuthorized=no [article] Stress-block parameters for unconfined and confined concrete based on a unified stress-strain model [texte imprimé] / Madhu M. Karthik, Auteur ; Mander, John B., Auteur . - 2011 . - pp. 270-273. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 137 N° 2 (Fevrier 2011) . - pp. 270-273 Mots-clés : Concrete  Stress  strain  Stress  blocks  Confined  concrete  Moment  curvature Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Equations to obtain equivalent rectangular stress-block parameters for unconfined and confined concrete are derived for rapid (hand) analysis and design purposes. To overcome a shortcoming of existing commonly used stress-strain models that are not easy to integrate, a new stress-strain model is proposed and validated for a wide range of concrete strengths and confining stresses. The efficacy of the equivalent rectangular stress-block parameters is demonstrated for hand calculations in predicting key moment-curvature results for a confined concrete column. Results are compared with those obtained from a computational fiber-element analysis using the proposed stress-strain model and another widely used existing model; good agreement between the two is observed. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i2/p270_s1?isAuthorized=no