This collection contains 37 papers presented at the Eleventh International Conference on Superplasticizers and Other Chemical Admixtures in Concrete in Ottawa, Canada. in July 2015. Topics include, Effect of Clinker Grinding Aids on Static Yield Stress of Cement Pastes, New Additive to Enhance the Slump Retention, Mastering Flow Loss in Superplasticized Cementitious Systems, and much more.