<p>To meet the carbon emission challenges posed by the large-scale application of traditional cement-based materials, incorporating industrial by-products at high dosages into high-performance concrete serves as a sustainable strategy. Based on this approach, low-carbon high-performance concrete (LC-HPC) has been developed, featuring low carbon emissions alongside high strength and high toughness. This study investigates the emission reduction potential, strength, peak strain, stress–strain relationship, and their stochastic properties of high-performance concrete incorporating high dosages of industrial by-products through a comprehensive experimental program involving 360 specimens across 10 groups, subjected to uniaxial and splitting tensile tests. The key variables include the cement replacement ratio (<i>r</i>_CRR), steel fiber (SF) volume fraction, and polypropylene fiber (PF) volume fraction, which are considered random factors potentially influencing tensile performance. Results demonstrate that incorporating industrial by-products can reduce carbon emissions in LC-HPC by 49.49% to 65.66% compared to conventional high-performance concrete. Meanwhile, the incorporation of hybrid fibers improves peak tensile stress by 42.7% and peak tensile strain by 54.0%, while also substantially enhancing residual stress and ductility. Notably, PF contributes to mitigating the high variability introduced by SF, reducing the coefficient of variation in peak stress and peak strain by up to 30.25% and 44.85%, respectively. Based on the test results, a new stochastic stress–strain model for LC-HPC tensile behavior is developed and validated, which can effectively predict the uniaxial tensile stochastic mechanical response, thereby providing a reliable theoretical basis and technical support for the refined design and stochastic evaluation of LC-HPC structural performance.</p>