SPN's structural testing services cover concrete and rebar testing, inspection of existing foundations and piles, floor, bridge and road load tests, and damage and condition assessment of buildings. Most work needs no demolition and the building stays in normal use. Results are summarized in a report signed by a COE-licensed engineer to support decisions on repair, extension, or buying and selling a building.
Non-Destructive Evaluation (NDE) assesses the condition of a structure using sound waves, electromagnetic waves and small-diameter sampling while the building stays in normal use. SPN's services range from concrete strength testing, locating rebar and voids, and assessing existing foundations without drawings, to floor, bridge and road load tests, post-fire and post-earthquake damage assessment, and surveys of adjacent buildings before construction.
Choose the symptom or purpose closest to yours. The test sets below are a starting point — the engineer will adjust the tests and number of points to actual site conditions.
Every report is signed by a licensed engineer. Tests can be combined to suit the purpose of the job.
There are 4 methods: Core Drilling & Compressive Strength, Rebound Hammer, Ultrasonic Pulse Velocity (UPV) and the Carbonation Depth Test, used to assess compressive strength, uniformity and service life of concrete in the actual structure.
Cylindrical concrete cores are drilled and tested for actual compressive strength in the laboratory. This gives the most accurate values and is used to confirm suspected or disputed quality.
A fast test of concrete surface hardness, converted to an estimated compressive strength. Suited to preliminary surveys of wide areas before choosing core locations (see the on-site test procedure)
High-frequency sound waves are sent through the concrete to assess quality and uniformity, detect internal voids or cracks, and measure crack depth.
Measures the depth of carbonation with phenolphthalein to assess remaining service life and the risk of rebar corrosion.
Ground Penetrating Radar (GPR), Rebar Locator / Cover Meter, the Half-Cell Potential Test and Crack Mapping & Monitoring detect what cannot be seen inside the structure and below the ground surface.
Scans in 2 applications: concrete scanning for rebar, cover, voids and embedded pipes, and subsurface surveys for pipes, buried objects and underground cavities — detection depth depends on antenna frequency and site material conditions.
Identifies the position, size and cover depth of reinforcement without drilling. Used to plan before Core Drilling and to check bar placement against the drawings.
Measures the electrical potential of reinforcement through the concrete surface to produce a corrosion map and assess corrosion probability. Suited to old structures or harsh environments.
Surveys and maps cracks, measures width and length, and tracks changes with crack gauges to separate dormant cracks from cracks that are still growing.
The Parallel Seismic Test and Side Echo Test determine the length and integrity of existing piles, Foundation & Structural Inspection checks the foundation, and the Pull Out Test verifies the holding capacity of anchors in concrete.
Assesses the length of existing piles and foundations without demolition: a borehole is drilled parallel to the pile and the waves are measured. Suited to old buildings without construction drawings, before extension or repair.
Tests the integrity of piles and foundations whose heads cannot be reached by striking the side face in an excavated pit and recording the signal, based on the Low-Strain Integrity principle.
Tests the tensile capacity of anchor bolts, chemical anchors and threaded studs in concrete with a hydraulic jack and records the load-displacement curve, confirming holding capacity before installing machinery or steel structures.
Inspects footings, beams, columns and slabs, assessing damage, settlement and deterioration, with a report of maintenance recommendations.
Proven with real loads by a Floor Loading Test and bridge and pier load tests, or assessed from test results for warehouse floors under racks / forklifts, roads and yards for cranes / trailers, machine foundations, tank foundations, concrete columns, and by Structural Back Analysis.
Test loads are placed on the actual floor (water ponding, water tanks or sandbags), and deflection and recovery are measured to confirm the floor carries the required load before use.
Slab thickness and rebar are measured with GPR, or cores are taken to test concrete strength, then point loads from selective rack legs and forklift wheels are analyzed against the existing floor capacity before installation.
Tested with vehicles or known loads, measuring deflection with LVDTs and strain with strain gauges, as either a Diagnostic or Proof Load Test, to confirm vehicle load limits or support structural upgrade work.
Checks slab thickness and rebar, tests concrete strength and the subgrade (Plate Bearing), then analyzes wheel and outrigger loads against the capacity of the existing road or yard.
Checks cracks, concrete strength, rebar positions and settlement of old machine foundations, settled or tilted tank foundations, and cracked concrete columns, assessing remaining capacity before continued use or repair.
Back analysis from test results and site data to find the cause of damage, assess remaining capacity and plan structural strengthening.
Condition before and after the event is recorded by a Dilapidation Survey and Vibration Monitoring; post-fire and post-earthquake building assessments and pre-purchase/lease structural inspection (Technical Due Diligence) conclude whether the building can stay in use, needs repair, or needs strengthening.
Records the condition of neighboring buildings before foundation work or excavation starts, with a crack map, photos marked with location and date, and crack gauges, as evidence if a crack dispute arises.
Measures peak particle velocity (PPV) at adjacent buildings during pile driving, excavation or machine operation, against international reference criteria.
Checks heat damage to concrete and rebar with a condition survey, Core Test, UPV and Rebound Hammer, classifies the damage level, and assesses whether members can be repaired or must be replaced.
A rapid inspection classifies safety (green, yellow, red placards), followed by a detailed inspection with testing, to conclude whether the building can stay in use or needs repair and strengthening.
Inspects the structure, reviews documents and drawings, tests concrete and rebar at critical points, and assesses the existing foundation, summarizing the risks and required repairs before you decide to buy or lease.
Send photos of the problem, plans (if any) and your purpose. SPN engineers will help select the tests and number of points needed, with a quotation within 24 hours.
Real projects published on our website, with links to the full details
Test of a 32 cm thick cast-in-place RC slab, span 3.75 × 4.00 m, in a 2-storey building, ponded with water 64 cm deep (640 kg/m²) held for 24 hrs. Measured deflection 0.50 mm, passing ACI 318-19 Chapter 27.
Parallel Seismic tests on 2 piles found pile tips at about 22.60–23.35 m depth, plus soil boring BH-1 to 30.45 m in the same project, giving a common reference level for the building upgrade.
Chemical anchor pull-out tests (Pull-Out Test) and concrete coring (Concrete Core Test) on a completed concrete structure in Chon Buri.
From the day you send photos of the problem to the certified report — actual duration depends on the number of points and tests.
Tell us the location, building age, plans (if any), photos of cracks or suspect areas, and your purpose, by LINE, phone or email.
The engineer selects test methods, number of points and report level to match your purpose, with a quotation within 24 hours.
Most field work takes 1 day and can be done in occupied buildings. Every test point is marked and photographed.
Cores are tested for compressive strength in the laboratory, taking about 7–14 days.
All methods are processed together and compared with standard criteria to assess remaining capacity and the cause of damage.
Report signed by a COE-licensed engineer with repair recommendations — GPR, Rebound Hammer and UPV reports ready within 3–5 working days after the site visit.
Non-Destructive Evaluation (NDE) assesses the strength, quality and internal condition of concrete structures, reinforcement and foundations without damaging the existing structure. It uses tools such as GPR, Ultrasonic Pulse Velocity, Rebound Hammer and the Parallel Seismic Test to answer whether a structure is still strong enough for use or extension, or needs repair.
SPN Soil Engineering provides end-to-end non-destructive structural testing (Non-Destructive Evaluation / Structural Testing), covering concrete quality assessment, defect detection, assessment of existing foundations, load testing and building damage assessment for buildings, bridges, factories and special structures of all types. Test results are certified by a licensed engineer and can be submitted to the relevant agencies.
Tests that assess compressive strength, quality and service life of concrete structures without destroying the existing structure.
Tests that use electromagnetic waves and advanced technology to detect anomalies inside structures and underground.
Tests to assess piles, existing foundations and the holding capacity of fixings in concrete.
Work that confirms floors, bridges, roads and foundations can carry new service loads, by testing with real loads or by assessment from test results combined with calculation.
Work that records condition before and after an event and assesses whether a building can stay in use, needs repair, or needs strengthening.
← Scroll to see the full table →
| Test | Standard | Output | Used for |
|---|---|---|---|
| Core Drilling | ASTM C42 | f'c (MPa) | Confirming actual concrete strength |
| Rebound Hammer | DPT 1502-51 / ASTM C805 | Rebound No. | Fast preliminary survey |
| Ultrasonic Pulse Velocity | ASTM C597 / DPT 1504-51 | Vp (m/s) | Quality / voids in concrete |
| Carbonation Depth | BS EN 14630 | Depth (mm) | Remaining service life |
| Ground Penetrating Radar | Concrete scan: DPT 1507-51 / ACI PRC-228.2 · Subsurface: ASTM D6432 | Radargram | Rebar, voids / pipes, buried objects |
| Rebar Locator | DPT 1505-51 / BS 1881-204 | Position / cover | Rebar positions |
| Half-Cell Potential | ASTM C876 / DPT 1506-51 | mV vs CSE | Corrosion risk |
| Crack Mapping | In-situ | Crack map | Crack survey and monitoring |
| Pull Out Test | ASTM E488 | Load (kN) | Anchor bolt holding capacity |
| Parallel Seismic Test | ASTM D8381 | Length (m) | Pile/foundation length |
| Side Echo Test | DPT 1551-51 | Reflectogram | Integrity of foundations with inaccessible pile heads |
| Floor Loading Test | ACI 318 Chapter 27 / ACI 437.2 | Deflection (mm) | Floor load capacity |
| Foundation & Structural Inspection | DPT 1501-51 / DPT 1902-62 | Inspection report | Condition of footings, beams, columns, slabs |
| Structural Back Analysis | DPT 1902-62 | Analysis report | Find cause / strengthening |
| Warehouse floor assessment for racks / forklifts | GPR · Core · Floor Load Test | Thickness / f'c / floor capacity | Installing racks on an existing floor |
| Bridge and pier load test | AASHTO MBE / ACI 437.2 | Deflection / Strain | Confirming vehicle load limits |
| Road/yard assessment for cranes | GPR · Core · Plate Bearing | Thickness / f'c / subgrade bearing | Crane setup, trailer traffic |
| Machine foundations / tank foundations / concrete columns | Core · UPV · Rebar Scan | Assessment report | Continued use, repair or strengthening |
| Dilapidation Survey | Crack Map / Crack Gauge | Condition report with photos | Evidence before adjacent construction |
| Vibration Monitoring | DIN 4150-3 / BS 7385-2 | PPV (mm/s) | Controlling vibration at adjacent buildings |
| Post-fire building assessment | DPT 1902-62 / ACI 562 | Damage level | Repair or replace members |
| Post-earthquake building inspection | ATC-20 / DPT 1902-62 | Green / yellow / red placards | Continued use or repair and strengthening |
| Technical Due Diligence | Core · UPV · Rebar Scan | Risk report | Before buying or leasing a building |
Non-destructive structural testing has no fixed standard price, because each building needs a different set of tests and number of points. SPN therefore quotes per project from plans and photos of the problem, free of charge, with a reply within 24 hours.
| Factor | Effect |
|---|---|
| Tests and number of points | Rebound Hammer, UPV, Rebar Scan and GPR are charged by number of points/scan area · Core Drilling is charged per core, including laboratory compressive strength testing |
| Building size and access | Number of floors, heights needing scaffolding/boom lifts, and after-hours work in occupied buildings |
| Report level required | Test report, or structural safety assessment report with recommendations, signed by an engineer (COE license) |
| Distance to site | Travel and equipment mobilization costs are charged based on site distance |
Send plans (if any), photos of cracks or symptoms found, and your purpose (extension, purchase/sale, agency submission, post-disaster inspection) to LINE @spnth or info@spnth.com. Our engineer will recommend the necessary tests and send a free quotation — read how pricing works and compare price levels by method in NDT structural testing prices 2026; for pile testing prices (Seismic, PDA), see Pile testing prices 2026
Free quotation within 24 hoursSPN's structural testing engineers operate from our office in Bang Sao Thong, Samut Prakan, and regularly cover the following areas
Real work in the gallery above: GPR at old buildings in central Bangkok and Sathorn · Pull Out Test on a project in Chon Buri · UPV and Rebar Scan in an occupied office building · Parallel Seismic at existing building foundations
Send your site location for a free quotation within 24 hoursStructural Testing tests the structure as a whole, such as a Floor Loading Test or Pull Out Test that measures strength. NDE (Non-Destructive Evaluation) focuses on assessing internal condition without damage, such as GPR, UPV and Rebound Hammer. In practice the two are often combined for complete results.
The Rebound Hammer is fast and non-destructive, suited to preliminary surveys of many points in a short time, but it is less accurate than Core Drilling, which extracts real samples and tests their strength in the laboratory. We recommend surveying with the Rebound Hammer first, then selecting additional Core Drilling points in suspect areas.
GPR can detect many things in concrete and soil, including reinforcing steel (rebar), embedded pipes, voids, internal cracks, electrical cables and other buried objects. Detection depth is not a fixed value; it depends on the antenna frequency and the type/moisture of the material. Concrete scanning uses high-frequency antennas for resolution, while subsurface surveys in dry sand may reach about 2–3 m or more, and moist clay much less.
A Pull Out Test measures the tensile capacity of anchor bolts, chemical anchors, threaded studs and other fixings in concrete. It is common when installing heavy equipment such as factory machinery, large racks and shelving, steel structures, towers and bridges. Reports are certified by a licensed engineer and can be submitted to the relevant agencies. Read about the test method and ASTM E488 in our article Pull-Out Test for chemical anchors and threaded studs
PIT strikes the pile head directly with a hand hammer (per DPT 1551-51) and suits piles whose heads are accessible. The Parallel Seismic Test drills a borehole beside the pile and measures the waves, so it suits existing piles embedded in a footing or under a building where the pile head cannot be reached. Read more about PIT in our article Seismic Integrity Test
The Side Echo Test excavates a pit beside the footing, fixes a steel transfer block to the side face, strikes it with a hand hammer and records the signal with an accelerometer. It is an adaptation of the Sonic Echo / Low-Strain Integrity method per DPT 1551-51 and gives qualitative results on concrete continuity and joint locations. The Parallel Seismic Test (ASTM D8381) drills a borehole parallel to the pile and measures wave travel time through a tube, so it determines pile length more accurately. If the goal is to confirm length, choose Parallel Seismic; Side Echo suits cases where the side of the footing can be excavated and a preliminary integrity assessment is needed.
Carbonation is the reaction in which CO₂ from the air penetrates concrete and lowers its pH. When the carbonation front reaches the reinforcement, the steel starts to corrode and the concrete cracks and spalls. The Carbonation Depth Test measures this depth with phenolphthalein and is used to assess remaining service life and plan preventive maintenance.
Yes. Every SPN test report is certified by a COE-licensed civil engineer and can be used for building-permit submissions and to other relevant agencies.
Most field work takes 1 day, depending on the number of test points and the size of the area. Core samples must be moisture-conditioned per ASTM C42 before compressive strength testing in the laboratory, about 7–14 days in total. For other tests such as GPR, Rebound Hammer and UPV, the report is ready within 3–5 working days after the site visit.
The Half-Cell Potential Test measures the electrical potential of the reinforcement through the concrete surface, interpreted per ASTM C876: values more positive than −200 mV (vs. Cu/CuSO₄) indicate a greater than 90% probability of no corrosion, −200 to −350 mV is uncertain, and values more negative than −350 mV indicate a greater than 90% probability of corrosion. The results are used to produce a corrosion map that identifies the areas to repair first.
Test loads are placed on the floor according to a designed load layout, and deflection is measured at mid-span and edges with dial gauges or LVDTs throughout the 24–48 hour test, followed by recovery measurement after unloading. The results confirm that the floor carries its design load before it is put into service. Read the detailed procedure in our article Floor Load Test
It can be checked without breaking the floor. First, slab thickness and rebar positions are measured with GPR, or cores are taken to test concrete strength. The engineer then calculates the point loads from rack legs and forklift wheels and compares them with the existing floor capacity. If the calculation is borderline, a Floor Load Test with real loads confirms it. Read more in our article How much load can factory and warehouse floors carry?
A Dilapidation Survey should record the condition of adjacent buildings before work starts, including photos marked with location and date, a map of existing cracks, and crack gauges on significant cracks. During pile driving or excavation, vibration (PPV) should be measured at adjacent buildings against the National Environment Board Notification No. 37 (B.E. 2553 (2010)) or DIN 4150-3 / BS 7385-2, as the project specifies. This data helps separate existing cracks from new ones if a dispute arises.
First, an engineer carries out a visual inspection to identify severely damaged members. Additional tests then follow at critical locations, such as Core Test and UPV to find the remaining concrete strength, Rebound Hammer surveys over wide areas, and inspection of exposed reinforcement. The assessment follows DPT 1902-62 together with ACI 562 (fire) or ATC-20 (earthquake), and concludes whether the building can stay in use, needs repair, or needs strengthening.
There is no fixed standard price, because each building needs a different set of tests and number of points. The fee depends on the tests (Rebound Hammer, UPV, Core Drilling, GPR, Rebar Scan, etc.), the number of points, building size and access, the report level required, and the distance to site. Send your plans and photos of the problem; our engineer will recommend the necessary tests and send a free quotation within 24 hours. Prices exclude travel and equipment mobilization costs, which are charged based on site distance.
Yes. Our engineering team works nationwide in all 77 provinces from our office in Bang Sao Thong, Samut Prakan, so we reach sites in Bangkok and its vicinity fastest. We have ongoing work in the East/EEC (Chon Buri, Rayong, Prachin Buri) and Central Thailand (Phra Nakhon Si Ayutthaya, Saraburi, Kanchanaburi), covering office buildings, factories and industrial estates. Travel and equipment mobilization costs are charged based on site distance.