Splitting Tensile Strength Of Concrete

2.1.8.4.2. Splitting tensile strength:

The splitting tests are well known as indirect tests used for determining the tensile strength of concrete. And sometimes it is referred to as split tensile strength of concrete. The split tensile strength is a more reliable technique to evaluate tensile strength of concrete (lower coefficient of variation) compared to other methods. The split tensile strength specimen of 150 mm diameter and 300 mm or 150 x150 mm cube specimen are placed between two plates with two pieces of 3 mm thick, as shown in figure (2.25). The test consists of applying a compressive line load along the opposite generators of a concrete cylinder placed with its axis horizontal between the compressive platens. (ESS 203) Figure (2.25):

In figure (2.26), eight equations proposed by different researchers have been plotted for lightweight concrete, as shown in table (2.12). The experimental splitting tensile strength values are calculated as follows: Eq. (2.23), (2.24), (2.25) (2.26) for cube specimens and (2.27), (2.28), (2.29), (2.30) for cylinder specimens. The splitting tensile strength of lightweight concrete for Eq. (2.23) ranged from 2.8 – 3.5 MPa, as shown in figure (2.23).

Eq. number Relation between the splitting and compressive strength Reference

2.23 fct = 0.487(fcu)0.5 Shafigh, Jumaat, Ahmud, Anjang, Hamid, (2012)

2.24 fct = 0.20(fcu)0.67 Shafigh, Jumaat, Ahmud, Anjang, Hamid, (2010)

2.25 fct = 0.23(fcu)0.67 Smadi and Migdady,

The two properties were usually used to estimate the tensile strength of concrete; however, they didn’t usually yield the same results. Taguchi's optimization technique was employed to reduce the number of trials needed to get the results. The results showed that the splitting tensile strength ranged between 60-80% of the modulus of rupture which was also known as the flexural strength.

2.1.8.4.3.2. For lightweight foamed concrete:

(Engg, 2013), investigated the structural properties of foamed concrete with and without pulverized bone. The tensile strength was evaluated by subjecting 150 x 150 x 750 mm unreinforced foamed concrete beams to flexural test and 150 x 300 mm cylinder specimens were subjected to splitting test. At the designed density of 1600 kg/m3, the modulus of rupture and splitting tensile strength were 2.53 and 1.63 MPa respectively with ratio of 0.64.

The ratio of flexural strength to compressive strength of lightweight foamed concrete (LWFC) was in the range of 0.06-0.10 and this ratio was also found to reduce with increasing water-cement ratios and decreasing densities (Deijk, 1991). The splitting tensile strengths of LFC mixes were higher for mixes with sand than those with fly ash. This was attributed to the improved shear capacity between sand particles and the paste phase. (Jones and McCarthy, 2005)