Nacim Khelil and  Amar Kahil and  Said Boukais,  Mechanical Contribution of Silica Fume and Hydrated Lime Addition in Mortars Assessed by Ultrasonic Pulse Velocity Tests .   journal   = {International Journal of Structural and Construction Engineering}, [online]. World Academy of Science, Engineering and Technology.
    October 2019, vol. 155(11). 677 - 681
    [viewed 21 January 2022]. Available from: https://publications.waset.org/pdf/10010878.