This dataset is used and fully described/interpreted in the paper: Passelegue, F. X., N. Brantut, T. M. Mitchell, Fault reactivation by fluid injection: Controls from stress state and injection rate, submitted to Geophys. Res. Lett. Text files contain raw and processed data. Mechanical data are raw. Load needs to corrected (offset) from piston friction, measured at the beginning of each run before the hit point. Axial displacement is converted into sample shortening by correcting the load from machine stiffness, which is equal to 480 kN/mm (calibrated on Mon. 14 Mar. 2016). Data include a set of elastic wave first arrival times, obtained from time of flight measurements using an array of piezoelectric transducers and the cross-correlation method detailed in Brantut (2015) (see reference above). Two separate files correspond to mechanical data from experiments conducted at 50 and 100 MPa confining pressure (""mech_Pc=???MPa.txt""). One file (""sensors.txt"") contains the initial positions of each piezoelectric transducer. Files named ""wave_?_Pc=100MPa.txt"" (?=1,2,3 or 4) contain time series of arrival times during the four injections conducted at Pc=100MPa. Each column consists in the time-of-flight between a given pair of sensors (x->y, where x is the index of source sensor, and y is the index of the receiver sensor, as per their numbering in the ""sensors.txt"" file.) In all the data files, the first column corresponds to a common time basis, in seconds.