XXX. 



W. II. WARREN. 

 Fig. 8. 



phj-ll)- "i r i . ■: . j L J: i 4 |HJp#M^ g P"r^TT-T-^|:----|., j, ; ..jg 



40 80 120 160 200 240 280 320 360 days 



Abscissae = Age in days. Ordinates = Crushing force in 100 lbs. per sq. inch. 

 Cement, ' Tripod brand '; Nepean sand ; screenings ; bluestone l-§ inch gauge. 



Transverse strength of concrete. — In making transverse tests of 

 concrete, the beams were accurately supported on the end bearings 

 and loaded in the centre, so that the beam was maintained in a 

 horizontal position, having the three lines of contact of the end 

 supports and central edge where the load was applied in true parallel 

 planes. The beams were 3 feet long, 12 inches wide, and 12 inches 

 deep, prepared by ordinary workmen by filling timber moulds in a 

 similar manner to that described for the concrete cubes in Series II. 



The beams were placed upon supports in the testing machine, 

 27 inches centre to centre and loaded in the centre. The results 

 of these tests are recorded in Series V., and the modulus of rupture 

 was calculated from the following formula : — 



f- 



u> + 



T I 



b<P 



Where f= the modulus of rupture 



w = the breaking load applied at the centre 



a/ = the weight of the beam between the centres of supports 



b = the breadth 



d = the depth 



I = the span 



