This Paper Introduces A Novel, Cost-Effective, And Durable Strain Sensor With Exceptional Sensitivity And Resolution, Utilizing An Open-Ended Hollow Coaxial Cable Resonator (OE-HCCR). The OE-HCCR Is Characterized By Two Reflective Elements: A Metal Post That Connects The Inner And Outer Conductors At The Signal's Entrance, And A Terminal Flange Near The Coaxial Line's End, Establishing A Variable Gap. The Sensor Employs A Paired Anchor Ring In Conjunction With The Terminal Flange To Transduce And Direct Strain. Variations In The Gap Alter The Resonant Frequency By Modulating The Phase Of The Reflection Coefficient At The Cable's Terminus. Initial Calibration Revealed A Nonlinear Relationship Between The Gap Alteration And The Fundamental Frequency Shift, Achieving A Sensitivity Of 2.5 GHz/mm At A Minimal Gap Of 0.02 Mm. A Low-Temperature Dependence Of 7.887x10⁻⁵ Mm°C (Change In Gap Distance/Celsius) Was Obtained. The Stability Of The Sensor Was Investigated To Obtain A Standard Deviation Of ±2.8 KHz, Corresponding To A Gap Distance Of ±5 Nm And An Equivalent Strain Change Of ±0.06 Με. Real-Time Monitoring Of Mortar Shrinkage Over A 56-Day Period Using Three OE-HCCR Strain Sensors Alongside Three Optical Fiber Extrinsic Fabry-Perot Interferometer (EFPI) Based Displacement Sensors Highlighted Consistent Strain Increase, Although Discrepancies Arose From Sensor Placement And The Complex Nature Of Mortar Hydration. With Its Low Cost, Simplicity, Wide Dynamic Range, Stability, And High Sensitivity, This All-Mechanical Design Sensor Holds Significant Promise For Demanding Industrial Environments.