All prices on this website include VAT. “From” prices depend on floor area and scope.
EFITECNIC / MATERIAL DIAGNOSIS
High-alumina cement testing in Barcelona.
Understand the floor structure. Analyse the sample.
Inspection, concrete sampling, on-site phenolphthalein test and laboratory analysis. Information about the cement in the examined element, explained by your building surveyor.
350 €VAT included · Visit, sampling, laboratory and report On-site phenolphthalein test included
JOSÉ LUIS BLÁZQUEZ ROMERO · CATEB 14.103
ONE-WAY FLOOR / EDUCATIONAL SECTION MODEL
Sampling is destructive. Filling, closing the opening, repairs and painting are not included. Reinstatement must be arranged separately before scheduling extraction.
01 / LOOK INSIDE THE FLOOR STRUCTURE
What supports the floor above.
Separate the layers, rotate the section and follow the sample. A visual explanation of the construction system, without attributing a diagnosis to the model.
ONE-WAY FLOOR / 3D SECTION
One-way floor with joists and infill blocks.
Components working together.
Joists define the main load-bearing direction. Infill blocks sit between them, with a structural topping above. This example uses prestressed concrete joists; not all floors have this configuration.
The relevant material is in the joist.
The study focuses on concrete from the selected element. Ceiling plaster and infill blocks cannot replace that sample. Construction type and background are checked during the visit.
Access must be assessed before extraction.
The access panel is removed and supports and upper layers hidden to reveal the joist. You can tilt the view. The surveyor selects the actual sampling point without cutting reinforcement; the position shown is illustrative.
An identified sample, a specific result.
The fragment moves out of the joist opening and enlarges. The dashed line indicates its origin; wires remain continuous within the element. The sample is identified before laboratory dispatch. Destructive sampling; repairs not included.
Simplified model, not to scale. The open section and separated layers explain the system; they do not represent the dimensions or procedure of actual opening-up work.
02 / HIGH-ALUMINA CEMENT AND DETERIORATION
The material is not the diagnosis.
In residential buildings, the usual focus is certain precast concrete joists made with high-alumina cement. A joist being precast or prestressed does not prove it contains that cement.
Why it was used
High-alumina cement's rapid strength development favoured its use in precast construction. Building age and floor type guide the investigation but do not identify the material.
What can change
Transformation of hydrated cement compounds can alter concrete porosity and strength. Moisture, temperature and manufacturing conditions influence its progression.
What needs assessment
The element, damp signs, cracks, spalling and possible corrosion are examined. Interpretation requires context: damage alone does not identify the cement, and its presence does not automatically mean structural damage.
The aim is to obtain information about the sampled material. A sample alone cannot establish the condition of the entire structure or replace a full structural assessment.
A sample provides information. Professional judgement gives it context.
Repairs not included
The service does not fill or reinstate the opening. Reinstatement must be arranged separately; it must not be assumed that the area can be left without appropriate technical protection.
The sample
José Luis visits the property and extracts the sample at the agreed point, after assessing access and sampling feasibility.
The on-site check
Phenolphthalein is applied to a freshly fractured surface. It indicates alkalinity and carbonation; it does not identify high-alumina cement by itself.
The laboratory
The sample is sent to the laboratory for the commissioned analysis. Results and observations are recorded in the report, with their limitations.
03 / THE SAMPLE AND ITS INTERPRETATION
From material to information.
Phenolphthalein gives an indicative pH reading in the tested area. Laboratory analysis examines the sample: these are different checks.
PRESTRESSED INVERTED-T JOIST / SECTION DETAIL
Fragment without indicator. The detail shows the wires inside the joist remaining continuous.
Educational diagram, not to scale. The opening and fragment are enlarged; they do not indicate where or how much to extract. Colour does not identify high-alumina cement or measure strength.
PHENOLPHTHALEIN / ON SITE
Colour provides an indication. Context matters.
With a pink or purple colour change
Indicates higher alkalinity in the tested area. It does not identify cement type or measure strength.
Without a colour change
May be consistent with carbonation and lower alkalinity. Interpretation requires technical context.
Neither reading alone determines structural condition or confirms high-alumina cement.
What phenolphthalein does
It is an acid-base indicator. On a fresh fracture, pink or purple reveals a sufficiently alkaline area; no colour change may correspond to reduced pH. It does not provide an exact pH measurement.
What carbonation is
Atmospheric CO₂ reacts with cement components and can reduce concrete alkalinity. The indicator helps reveal this change, but its reading depends on the material and test conditions.
What the laboratory analyses
The test aims to identify the sample's cement type. As a technical reference, CATEB describes a method based on the BRE oxine test. The method used for your sample must be stated in the laboratory report.
The identification test alone does not measure strength, degree of conversion or safety of the whole floor. No specific laboratory or method is assigned to the job before confirmation.
The €350 includes the visit, extraction, on-site phenolphthalein, dispatch, laboratory analysis and report within the agreed scope. Closing the opening, repairs and painting are excluded.
If results suggest further investigation, this is agreed as a separate assignment. No additional checks are carried out without agreeing their scope.
04 / REAL VISUAL REFERENCES
Recognise the components. Interpret the signs.
Prestressed joist installation illustrating the construction type. This is a third-party photograph, not an EFITECNIC project.
Prestressed joists and infill blocks.Installation of a floor using precast prestressed concrete elements. The photograph illustrates the construction type; it does not imply the cement is high-alumina.Sahlianox / Wikimedia Commons · 2012 · CC BY-SA 3.0. Resized and converted to WebP; adaptation under the same licence.Technical reference awaiting addition.This space does not show an actual case. Reinforcement corrosion must be interpreted alongside inspection and laboratory results.
Do all precast joists contain high-alumina cement?
No. Precasting or prestressing does not identify the cement used. The floor type is reviewed and, where appropriate, a sample of the element analysed.
Are high-alumina cement and aluminosis the same?
No. High-alumina cement identifies a material type; aluminosis refers to deterioration processes requiring technical assessment. Structural damage must not be inferred solely from the cement's name.
What does phenolphthalein indicate?
The colour change helps interpret concrete alkalinity and carbonation at the tested point. It does not measure mechanical strength or independently confirm the presence or absence of high-alumina cement.
Does the test make a hole?
Sampling is destructive and leaves an opening or localised material loss. Size and location depend on assessment of the element and planned analysis.
Who reinstates the area?
Closing, repairs, plastering, painting and replacement finishes are not included. The customer must arrange this separately and follow appropriate technical instructions to protect the affected area.
What does the €350 include?
VAT, visit, sampling, on-site phenolphthalein test, dispatch, laboratory analysis and report within the agreed assignment. Any additional samples or investigation are scoped before proceeding.
Does the result apply to the whole building?
No. Analysis concerns the sampled material. Variation within the building or observed defects may require further checks and a separate study.
When will I receive the result?
Timing is confirmed when arranging the assignment and depends on the laboratory. No immediate result is promised during the visit.
Do I need permission to extract the sample?
Appropriate authorisation and access are required. If the point affects communal or structural elements, conditions are agreed before starting.
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Technical services in Barcelona and Baix Llobregat
José Luis Blázquez Romero, EFITECNIC building surveyor, CATEB member no. 14.103, with over 15 years of experience. Serving Barcelona, Viladecans, Gavà, Castelldefels, L'Hospitalet de Llobregat, Cornellà de Llobregat, Sant Boi de Llobregat, Esplugues de Llobregat and Sant Feliu de Llobregat. Provide the municipality and property details to arrange the visit and scope.
