PSI - Issue 22

Maria da Luz Garcia et al. / Procedia Structural Integrity 22 (2019) 166–170 Maria da Luz Garcia, Rosário Oliveira/ Structural Integrity Procedia 00 (2019) 000 – 000

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2.4. Water absorption test by immersion at 48h The immersion water absorption test at 48 hours at atmospheric pressure was performed on prismatic specimens 160 × 40 × 40 mm (lower values or specification) according to the specification LNEC E 394 at 46 days of age, in the applicable part. The water absorption content by immersion expressed as a percentage, A, is obtained by the following equation, Eq.2. A = ( (m 1 − m 3 )/(m 1 − m 2 ) ) × 100 (2) At where: m1- mass of the air-saturated test piece, expressed in grams; m2 - hydrostatic mass of the saturated test specimen expressed in grams; m3 - mass of the dry test specimen expressed in grams. Based on the results obtained (Table 1), it was confirmed that hydraulic lime mortar is the one with the highest water absorption by immersion. 2.5. Pull off test The pull-off test was performed according to the procedures of European standard EN 1015-12. As the standard does not specify the type of support element using, performed to the test "in situ" in order to obtain more authentic values, that is, the support element is a granite stone masonry of an old building, with a rough and porous surface. This test allows us to quantify the adhesion stress and characterize the type of failure shown in Table 2. Tab. 2. Values of the adhesion tension and rupture typology

Number of tests

Mortar

σ Máx (MPa) σ Mín (MPa) σ Méd (MPa)

Type of rupture

5

3,136

1,045

1,699

cohesive

AHL

5

0,627

0,47

0,549

cohesive

AWC

In all tests the mortar presented a cohesive break of the mortar, that is to say mortar is less cohesive than adherent, besides, as can be observed in table 2 AHL mortar presents values of tension of adhesion superior to that of mortar AWC. 3. Conclusions We present a joint analysis of the limit values of properties in old building renovation mortars recommended by the LNEC Rosário Veiga researcher together with the values obtained in the experimental part of AHL and AWC mortars, Table 3. Tab. 3. Properties results determined in AHL and AWC mortar Property Units AHL AWC Veiga (2008)