{"id":18024,"date":"2025-09-18T07:56:50","date_gmt":"2025-09-18T07:56:50","guid":{"rendered":"https:\/\/support.buildsoft.eu\/docs\/12build\/analysis-dimensioning\/reinforcement-calculation\/"},"modified":"2026-01-06T08:57:21","modified_gmt":"2026-01-06T08:57:21","slug":"reinforcement-calculation","status":"publish","type":"docs","link":"https:\/\/support.buildsoft.eu\/es\/docs\/12build\/analysis-dimensioning\/reinforcement-calculation\/","title":{"rendered":"Reinforcement calculation"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">Concrete parameters<\/h2>\n\n\n\n<p style=\"font-size:16px\">Based on the concrete quality you have selected, 1\u20222\u2022Build determines the corresponding properties that are used in the reinforcement calculation. Although you, as the user, cannot manually set all the parameters described below, they are of course included in the calculation note for concrete elements.<\/p>\n\n\n\n<ul>\n<li>The <strong>characteristic compressive strength of the concrete f<sub>ck<\/sub><\/strong> at an age of 28 days. 1\u20222\u2022Build will apply a safety factor of 1.5 to this, in accordance with Eurocode.<\/li>\n\n\n\n<li>The <strong>modulus of elasticity of the concrete E<sub>c,28<\/sub><\/strong> at an age of 28 days.<br>1\u20222\u2022Build sets this standard to the secant modulus of the concrete and calculates it automatically based on the characteristic compressive strength of the concrete f<sub>ck<\/sub>. This is included in the calculation of the concrete stresses.<\/li>\n\n\n\n<li>The <strong>creep coefficient \u03c6(t,t<sub>0<\/sub>)<\/strong><br>1\u20222\u2022Build determines the creep coefficient in such a way that the ratio between the modulus of elasticity of steel E<sub>s<\/sub> (200000 N\/mm\u00b2) and that of concrete after creep E<sub>c<\/sub> (=E<sub>c,28<\/sub>\/(1+\u03c6)) is equal to 15.<br>The creep factor in 1\u20222\u2022Build only intervenes in the calculation of concrete stresses. 1\u20222\u2022Build limits the concrete stress in a BGT ZC combination to 0.6\u2219f<sub>ck<\/sub> and in a BGT QP combination to 0.45\u2219f<sub>ck<\/sub>, in accordance with Eurocode.<br>The creep factor in 1\u20222\u2022Build is NOT used to calculate any cracked deflections with\/without creep. This is not possible in 1\u20222\u2022Build. 1\u20222\u2022Build only shows the elastic deformations.<\/li>\n\n\n\n<li>Finally, if necessary, 1\u20222\u2022Build will increase the reinforcement to solve any buckling problems. The buckling is verified using the method based on the nominal curvature (EN 1992-1-1 \u00a75.8.8). This method requires a random eccentricity that takes into account a possible skew. 1\u20222\u2022Build sets the accidental eccentricity equal to 20 mm.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Reinforcement parameters<\/h2>\n\n\n\n<p style=\"font-size:16px\">Based on the yield strength f<sub>yk<\/sub> you have selected for the reinforcing steel and reinforcement cover, 1\u20222\u2022Build determines the corresponding properties that are used in the reinforcement calculation. Although you, as the user, cannot manually set all the parameters described below, they are of course included in the calculation note for concrete elements.<\/p>\n\n\n\n<ul>\n<li>1\u20222\u2022Build uses the yield strength f<sub>yk<\/sub> for both longitudinal and transverse reinforcement (stirrups).<\/li>\n\n\n\n<li>1\u20222\u2022Build applies a safety factor of 1.15 to the yield strength f<sub>yk<\/sub>, in accordance with Eurocode.<\/li>\n\n\n\n<li>Reinforcement cover is defined as the distance from the centre of gravity of the reinforcement to the edge of the concrete cross-section.<\/li>\n\n\n\n<li>If a certain amount of reinforcement is required for the force to be exerted, this is increased to the minimum reinforcement percentage (0.15%) if necessary.<\/li>\n\n\n\n<li>If the maximum reinforcement percentage is exceeded, 1\u20222\u2022Build displays a skull and crossbones in the relevant elements.<\/li>\n\n\n\n<li>1\u20222\u2022Build limits the steel stress in a BGT ZC combination to 0.8\u2219f<sub>yk<\/sub> in accordance with Eurocode.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Calculation<\/h2>\n\n\n\n<p style=\"font-size:16px\">For the theoretical background of the reinforcement calculation, we refer to Eurocode 2 and to Part 3 of this reference manual on calculating in accordance with the Eurocodes (only available in <a href=\"https:\/\/downloads.buildsoft.eu\/pdf\/nl\/Referentiehandleiding%2012Build%20-%20Deel%203.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">Dutch<\/a> or <a href=\"https:\/\/downloads.buildsoft.eu\/pdf\/fr\/Manuel%2012Build%20partie%203.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">French<\/a>).<\/p>\n\n\n\n<p class=\"wp-block-ht-blocks-messages wp-block-hb-message wp-block-hb-message--withicon is-style-alert\">It is important to note that the deflection calculated by 1\u20222\u2022Build is always the elastic deflection and that it does not take into account the effects of cracking, shrinkage or creep. The actual deflection of concrete elements can be 3 to 5 times greater than this elastic deflection, depending on the degree of cracking of the concrete elements. As mentioned, 1\u20222\u2022Build does not allow this to be taken into account. However, this is possible with more advanced calculation packages such as ConCrete or Diamonds.<\/p>\n\n\n\n<p style=\"font-size:16px\">Below is an example of the bottom and top reinforcement for a simple beam.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full is-resized\"><a href=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2025\/09\/image-62.png\"><img decoding=\"async\" loading=\"lazy\" src=\"https:\/\/support.buildsoft.eu\/wp-content\/uploads\/2025\/09\/image-62.png\" alt=\"\" class=\"wp-image-18031\" width=\"480\" height=\"99\"\/><\/a><\/figure>\n\n\n\n<p style=\"font-size:16px\">The thin line represents the amount of reinforcement required to meet only the ultimate limit state. The thicker line represents these amounts increased to take into account the limitation of stresses in the serviceability limit states, while respecting minimum reinforcement percentages and any risk of buckling.<\/p>\n","protected":false},"featured_media":0,"parent":17855,"menu_order":6,"comment_status":"closed","ping_status":"closed","template":"","doc_tag":[],"comment_count":0,"_links":{"self":[{"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/docs\/18024"}],"collection":[{"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/docs"}],"about":[{"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/types\/docs"}],"replies":[{"embeddable":true,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/comments?post=18024"}],"version-history":[{"count":15,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/docs\/18024\/revisions"}],"predecessor-version":[{"id":23307,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/docs\/18024\/revisions\/23307"}],"up":[{"embeddable":true,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/docs\/17855"}],"next":[{"title":"Buckling length calculation","link":"https:\/\/support.buildsoft.eu\/es\/docs\/12build\/analysis-dimensioning\/buckling-length-calculation\/","href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/docs\/22502"}],"prev":[{"title":"Verification of steel and timber","link":"https:\/\/support.buildsoft.eu\/es\/docs\/12build\/analysis-dimensioning\/verification-of-steel-and-timber\/","href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/docs\/22981"}],"wp:attachment":[{"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/media?parent=18024"}],"wp:term":[{"taxonomy":"doc_tag","embeddable":true,"href":"https:\/\/support.buildsoft.eu\/es\/wp-json\/wp\/v2\/doc_tag?post=18024"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}